2003 Dodge Ram ECU swap Questions

[LilSick]

Not a worry but a consideration. Not just for longevity but for what the torque curve is gonna look like too. Five thou is a butt ton of taper - happiness is a round straight hole : )

[PurpleRam]

"I tore that 468 apart in March 2019, cylinders had on average.007 tapper, with #8 being the worst@ .010."

Yeap that's a good amount of cylinder wear.........now keep in mind that 468 made 740hp @7600 ,630 FT @5400(ish) when built, 28k miles later, close to 250passes , he was still driving it to the track( 40 min drive) roll in, pass tech, and run a 10.90@123/124 MPH weighing in at 4950 with a 1/2 tank of 93oct.

The 540 Big Chevy I pulled apart this past weekend, has 15k miles on it and not one cylinder has less then .012 taper and that chunk of Chevy never went over 7k in it's short-lived life(I don't believe it either, He had to hit 7200-7500 once in a while.)


Yes having a straight bore that is round and having no taper is the best for producing the most HP, But 99.9% of the time, not many are straight. Most bores start out with .005 out of round and .010 taper then with proper finishing machine work (bore and hone) the final fit with a hone will net you+/-.001 to .0015,
Now OEM standards on average are,Max Taper .00051",Max Perp .0020", Dia. = +/- .005" but yet No OEM engine will be less the .002 taper after 25k miles, I don't care what it is, Toyota, Honda , BMW(those can be HORRIBLE)
I haven't received a BGE, LSX, Dart SHP, Callies block that didn't start out with less than .005 taper. Most LSX's we would beat to a pulp in our Trans am program, at the end of the season, they were in .005-008 range......with 1.9 to 1.95 Rod ratio.

Last example when we did endurance testing on the 1st gen Coyotes, all 20 engines when tore down averaged .08 taper after 3500 hours at 2500RPMs. and they are 1.62 RR

[LilSick]

Imagine ring end gap in a engine with 010 taper

Put that one in the trailer first

[ineedtofinishmyprojects]

Imagine ring end gap in a engine with 010 taper

Put that one in the trailer first

Yep, you knowledge is just what I thought it would be... Not one bit of actual experience... Why are you dead set on this conversation?

[PurpleRam]

Imagine ring end gap in a engine with 010 taper

Put that one in the trailer first

Yeap ring gap went from being a little tight for NA, too just right for NOS

[ineedtofinishmyprojects]

Understand this has been my experience, My current crop of 02-05 RC4x2 Rams consist of 12 , 4 strictly drag trucks, 6 daily's and two projects ,

1st I would drop the side tank and go with a Mustang/Universal tank, mount it under the bed where the spare tire goes?.(which you might have already do when going 4 link)makes true equal length duals a reality, also lets you mount both shocks on the bac side of the axle in a 10-15* position in relationship to the rear axle.
2nd JTS Venom, They have a Spider gear set for the Dana SRT10 Dana?..the oem spiders are almost as weak as a RFE545 Trans?.(almost) JTS also has a lot of T56 goodies for your swap.
3rd JMB performance SRT10 Battery relocation kit??it?s a one stop kit.
4th If you plan on driving a good amount, I mean 75-100 miles a week, or you know you want to do 100mile road trips??.Cowl Hood, similar to the OEM Ram GTX hood ??. As you know from owning your truck as long as you have , half of the dam engine is under the cab over hang?..these things build up a ton of heat especially when you get in to the 400+CI engines.
As much as I think the Us-bodies Super-bee hood is just plan ole Awesome looking on these trucks. Cowl is the go-to, 2nd hood that works well on these is a 6pk Scoop hood.

Back in 2010 I helped my niece?s late husband build a 433ci 5.7 (4.03X4.25) it used Nissian application 6.077 rods, so rod ratio is a measly 1.43 , it went in to her 06 C300, she wrecked the car in 2016 with 90k on the 433, we dropped it in to her new(for her) 08 Magnum. 2020 the car was striped, and chassis was sold off to a neighbor of hers. The 433 had 155k on it when I tore it down. Taper was less then .005 on all 8 cylinders.

I have a good friend who runs 8.2 deck ht SBF's his favorite combo I build for him is 4.185X3.79 he tops it off with 4 plates of NOS, he runs a lot of small tire races nation wide in a 83 Fox Body , we run 5.234Honda style rods, rod ratio is 1.38 He averages 10k miles a year , we rebuild or replace every year, but this last Dart block had 3 rebuilds on it this current "rebuild" I cut the block .005 to clean up the tapper in cylinder 6 & 8

I think too many people worry about Rod ratio now-adays , Plenty of Small block chevy 400s out there with 1.48 Rod ratio

I was planning on a Rhodes gas tank in the spare location. The panard bar rubs the plastic one, and like you said I want to run my exhaust out the side right under where it is now.
I've heard of this spider gear upgrade, was planning on an Eaton True Track too.
Battery relocation is also a good idea, I'll look at it.
I live in Florida, so anything for cooling is a good idea. I have an electric fan, but planned on getting a bigger radiator with the motor upgrade. If you saw a big difference with a cowl hood I'll look at those too. My hood is losing the clear coat so I need to paint it anyways...

[rays04gtx]

we installed a Rhodes Part Number:18-3107 (GM truck 63-72 EFI Tank) in to a 02 ram that's in the shop, no issues , Rhodes makes some good stuff.

If you do a lot of creeper/crawling traffic Cowl hood is a good idea, I've been swapping back in fourth between my Daily 04 GTX and my Grandson's new to him 06SLT ,both have 180 t-sate , the GTX is usually 175-183 ECT the SLT gets as high 190 during the same drive to work.
Something you'll never deal with , but the GTX's windshield defrosts about 5 mins quicker @ 20 Degrees then my Daughters 05 Rumble Bee....just saying.

Are you keeping AC ? I know FLA is not a place were people are willing to give it up. reason I ask is , dumping AC allows you to center up the rad in the engine compartment, and that helps with keeping down Under hood air temps., what happens is , you free up space on both sides of the Rad, and that air flow coming through the grill, It's now directed over the headers and creates Postive pressure that pushes hot air out the Cowl hood,

Last winter the oldest kid and I built an 05 SLT Ram with a 431(BGE block build), used a Eagle Truck Intake modified a 09+ Vararam CAI set up ,looking at all the logs he sent us, it never got over ECT of 189F , owner is in Ohio , which granted doesn't see FLA type weather often.

[gstubbz]

I'm in the middle of a 2003 Ram 2500 5.7 545rfe to NV4500 swap myself, and a computer was a big concern of mine as 2003 is the oddball year and completely unreadable with HPTuners. I wanted to find an 05 computer to swap which would hopefully give me engine tuning ability and gear ratio / tire changes. I do have a manual trans 2003 computer but for sake of argument to at least get it running according to the 03 cummins guys you can just unplug the TCM entirely, jump the neutral safety switch and the truck will run. I cannot confirm that works with a Hemi truck, but I am going to test it in the next week or so to see if it works.

My end goal is just to put in a 2005 computer as it sounds like 2004 is just a minor less oddball than the 03 trucks, so I might as well go with the later one. I also can't confirm (yet) that you can use HPTuners to flash a 05 computer for a M/T from an A/T and have it work properly and remove the PRNDL on the cluster but I believe it's possible just like how it's done on the GM trucks.

Doesn't really help your situation but I feel like it was information worth mentioning.

[ineedtofinishmyprojects]

we installed a Rhodes Part Number:18-3107 (GM truck 63-72 EFI Tank) in to a 02 ram that's in the shop, no issues , Rhodes makes some good stuff.

If you do a lot of creeper/crawling traffic Cowl hood is a good idea, I've been swapping back in fourth between my Daily 04 GTX and my Grandson's new to him 06SLT ,both have 180 t-sate , the GTX is usually 175-183 ECT the SLT gets as high 190 during the same drive to work.
Something you'll never deal with , but the GTX's windshield defrosts about 5 mins quicker @ 20 Degrees then my Daughters 05 Rumble Bee....just saying.

Are you keeping AC ? I know FLA is not a place were people are willing to give it up. reason I ask is , dumping AC allows you to center up the rad in the engine compartment, and that helps with keeping down Under hood air temps., what happens is , you free up space on both sides of the Rad, and that air flow coming through the grill, It's now directed over the headers and creates Postive pressure that pushes hot air out the Cowl hood,

Last winter the oldest kid and I built an 05 SLT Ram with a 431(BGE block build), used a Eagle Truck Intake modified a 09+ Vararam CAI set up ,looking at all the logs he sent us, it never got over ECT of 189F , owner is in Ohio , which granted doesn't see FLA type weather often.

Thanks again for the detailed info, always helpful.

I really will be looking at a cowl hood, sounds like a worthy mod. Any particular brand or manufacturer that you had good luck with?

Ditching AC is really not an option, it's just too dang hot here.

[ineedtofinishmyprojects]

I'm in the middle of a 2003 Ram 2500 5.7 545rfe to NV4500 swap myself, and a computer was a big concern of mine as 2003 is the oddball year and completely unreadable with HPTuners. I wanted to find an 05 computer to swap which would hopefully give me engine tuning ability and gear ratio / tire changes. I do have a manual trans 2003 computer but for sake of argument to at least get it running according to the 03 cummins guys you can just unplug the TCM entirely, jump the neutral safety switch and the truck will run. I cannot confirm that works with a Hemi truck, but I am going to test it in the next week or so to see if it works.

My end goal is just to put in a 2005 computer as it sounds like 2004 is just a minor less oddball than the 03 trucks, so I might as well go with the later one. I also can't confirm (yet) that you can use HPTuners to flash a 05 computer for a M/T from an A/T and have it work properly and remove the PRNDL on the cluster but I believe it's possible just like how it's done on the GM trucks.

Doesn't really help your situation but I feel like it was information worth mentioning.

Thanks! Seems like the info we have is lining up, which is encouraging. please reply and let me know how it goes if take the leap.

Why NV4500? Not a performance build?

[gstubbz]

Thanks! Seems like the info we have is lining up, which is encouraging. please reply and let me know how it goes if take the leap.

Why NV4500? Not a performance build?

I have an update!

So when I completed the swap I actually used the manual trans computer for the first start, and my stock automatic gauge cluster showed PRNDL for a few seconds then it went away and hasn't come back since. It has kept my original truck mileage as well.

A few hours later I put in the stock automatic computer, and the gauge cluster still did not show PRND21. My neutral safety switch (dark green two prong plug next to the clutch pedal on the firewall) worked like it should and I had to depress the clutch pedal before the truck would start. The truck honestly runs fine on the automatic computer and my cruise even worked for a bit (but didn't want to today). The ONLY thing is I get a P1698 (PCM Fault no CCD) engine light but that's it. Truck runs absolutely fine otherwise. I am going to just leave the original automatic computer in the truck until I do the 05 swap.

I only went with an NV4500 because one from a hemi popped up on FB Marketplace (93k, $1000) and I wanted to manual swap my truck for the longest time. Literally a week from the day I picked up that NV4500 I came across a 2003 ram 2500 with a 5.7/nv4500 on FB Marketplace I bought for $2800 and used as a parts truck. Well I didn't need much for the manual swap so I think I'll just fix the parts truck and resell it to fund more mods for this truck. The NV4500 is definitely a slow shifting transmission. A stock 545RFE trans truck will absolutely walk all over in a race vs the NV4500, I think in part due to the nature of the transmission it's better suited for diesel trucks as the Hemi likes to rev and make power 3k rpm+. In addition if you like to go 80mph+ the nv4500 is not the right transmission it does not like it. I think for *most* people it may not be a terrible choice, but for 25 year old me I like to go fast and using a nv4500 was not the right decision for that. You can hold 70mph on slight hills in 5th gear but it likes to lose a lot of speed and doesn't hold it well (engine has less than 10k on a rebuild). I've driven cummins trucks with the same transmission and the low-end torque helps carry the truck and is not as noticeable as it is behind a gas engine.

But now that my swap is done, I am on the fence about either putting an automatic back in it, or swapping in a 05+ Hemi G56 transmission (they shift faster!) or trying out a Tremec TR-4050 5 speed (made to be a bolt in replacement for a nv4500). If the truck was a 1500 and not a 2500 that I will use to tow all the time, T56 all the way.

[LilSick]

hope you tacked the high gear nut or installed the right kit (two bolt)

still better off towing in 4th (imo)

[TaylorJ]

I have an update!

So when I completed the swap I actually used the manual trans computer for the first start, and my stock automatic gauge cluster showed PRNDL for a few seconds then it went away and hasn't come back since. It has kept my original truck mileage as well.

A few hours later I put in the stock automatic computer, and the gauge cluster still did not show PRND21. My neutral safety switch (dark green two prong plug next to the clutch pedal on the firewall) worked like it should and I had to depress the clutch pedal before the truck would start. The truck honestly runs fine on the automatic computer and my cruise even worked for a bit (but didn't want to today). The ONLY thing is I get a P1698 (PCM Fault no CCD) engine light but that's it. Truck runs absolutely fine otherwise. I am going to just leave the original automatic computer in the truck until I do the 05 swap.

I only went with an NV4500 because one from a hemi popped up on FB Marketplace (93k, $1000) and I wanted to manual swap my truck for the longest time. Literally a week from the day I picked up that NV4500 I came across a 2003 ram 2500 with a 5.7/nv4500 on FB Marketplace I bought for $2800 and used as a parts truck. Well I didn't need much for the manual swap so I think I'll just fix the parts truck and resell it to fund more mods for this truck. The NV4500 is definitely a slow shifting transmission. A stock 545RFE trans truck will absolutely walk all over in a race vs the NV4500, I think in part due to the nature of the transmission it's better suited for diesel trucks as the Hemi likes to rev and make power 3k rpm+. In addition if you like to go 80mph+ the nv4500 is not the right transmission it does not like it. I think for *most* people it may not be a terrible choice, but for 25 year old me I like to go fast and using a nv4500 was not the right decision for that. You can hold 70mph on slight hills in 5th gear but it likes to lose a lot of speed and doesn't hold it well (engine has less than 10k on a rebuild). I've driven cummins trucks with the same transmission and the low-end torque helps carry the truck and is not as noticeable as it is behind a gas engine.

But now that my swap is done, I am on the fence about either putting an automatic back in it, or swapping in a 05+ Hemi G56 transmission (they shift faster!) or trying out a Tremec TR-4050 5 speed (made to be a bolt in replacement for a nv4500). If the truck was a 1500 and not a 2500 that I will use to tow all the time, T56 all the way.

Try unchecking P0700 in the Trouble code section of the tune.......that worked for me, Or see if you can get HP to add Code 1698, it's there in the OS system, HP for some reason doesn't have it
Tr4050 shifts lie a TKO 600 , I like the Getrag myself.

[TaylorJ]

I'm in the middle of a 2003 Ram 2500 5.7 545rfe to NV4500 swap myself, and a computer was a big concern of mine as 2003 is the oddball year and completely unreadable with HPTuners. I wanted to find an 05 computer to swap which would hopefully give me engine tuning ability and gear ratio / tire changes. I do have a manual trans 2003 computer but for sake of argument to at least get it running according to the 03 cummins guys you can just unplug the TCM entirely, jump the neutral safety switch and the truck will run. I cannot confirm that works with a Hemi truck, but I am going to test it in the next week or so to see if it works.

My end goal is just to put in a 2005 computer as it sounds like 2004 is just a minor less oddball than the 03 trucks, so I might as well go with the later one. I also can't confirm (yet) that you can use HPTuners to flash a 05 computer for a M/T from an A/T and have it work properly and remove the PRNDL on the cluster but I believe it's possible just like how it's done on the GM trucks.

Doesn't really help your situation but I feel like it was information worth mentioning.

I know I'm late to the party here, but Yes the Cummins guys are correct(as you found out)

the Auto ECU is fine, just click it to manual , wire up a clutch switch (use it as a security kill switch) Un check P0700 in the trouble codes and your Off and running, word to the wise table 13512 (engine displacement set it to 0Liter

[ineedtofinishmyprojects]

I have an update!

So when I completed the swap I actually used the manual trans computer for the first start, and my stock automatic gauge cluster showed PRNDL for a few seconds then it went away and hasn't come back since. It has kept my original truck mileage as well.

A few hours later I put in the stock automatic computer, and the gauge cluster still did not show PRND21. My neutral safety switch (dark green two prong plug next to the clutch pedal on the firewall) worked like it should and I had to depress the clutch pedal before the truck would start. The truck honestly runs fine on the automatic computer and my cruise even worked for a bit (but didn't want to today). The ONLY thing is I get a P1698 (PCM Fault no CCD) engine light but that's it. Truck runs absolutely fine otherwise. I am going to just leave the original automatic computer in the truck until I do the 05 swap.

I only went with an NV4500 because one from a hemi popped up on FB Marketplace (93k, $1000) and I wanted to manual swap my truck for the longest time. Literally a week from the day I picked up that NV4500 I came across a 2003 ram 2500 with a 5.7/nv4500 on FB Marketplace I bought for $2800 and used as a parts truck. Well I didn't need much for the manual swap so I think I'll just fix the parts truck and resell it to fund more mods for this truck. The NV4500 is definitely a slow shifting transmission. A stock 545RFE trans truck will absolutely walk all over in a race vs the NV4500, I think in part due to the nature of the transmission it's better suited for diesel trucks as the Hemi likes to rev and make power 3k rpm+. In addition if you like to go 80mph+ the nv4500 is not the right transmission it does not like it. I think for *most* people it may not be a terrible choice, but for 25 year old me I like to go fast and using a nv4500 was not the right decision for that. You can hold 70mph on slight hills in 5th gear but it likes to lose a lot of speed and doesn't hold it well (engine has less than 10k on a rebuild). I've driven cummins trucks with the same transmission and the low-end torque helps carry the truck and is not as noticeable as it is behind a gas engine.

But now that my swap is done, I am on the fence about either putting an automatic back in it, or swapping in a 05+ Hemi G56 transmission (they shift faster!) or trying out a Tremec TR-4050 5 speed (made to be a bolt in replacement for a nv4500). If the truck was a 1500 and not a 2500 that I will use to tow all the time, T56 all the way.

Dude, now THIS is some good information, THANK YOU!!

I've found many examples of people swapping an 03 ECU to an 05 ECU (for use with a manual transmission), and lots of examples of people swapping an auto to a manual using a manual transmission ECU, but so far nobody that has actually confirmed using an auto trans ECU for a manual swap. Lots of people saying it SHOULD work, but not anyone who has confirmed it. This is awesome.

I was just curious about your transmission choice, but I see your reasons. A T56 would be pretty unwieldly for towing...

Thanks again...

[ineedtofinishmyprojects]

I know I'm late to the party here, but Yes the Cummins guys are correct(as you found out)

the Auto ECU is fine, just click it to manual , wire up a clutch switch (use it as a security kill switch) Un check P0700 in the trouble codes and your Off and running, word to the wise table 13512 (engine displacement set it to 0Liter

Will unchecking P0700 also turn off the engine light for P1698, or is that stil going to keep the light on? What does setting table 13512 to 0 Liters do for me?

Thanks!

[PurpleRam]

Will unchecking P0700 also turn off the engine light for P1698, or is that stil going to keep the light on? What does setting table 13512 to 0 Liters do for me?

Thanks!

1st, 13512, setting to 0 disables what little ESP there is in these trucks.
2nd p0700, worked on Taylor’s 05, didn’t work on my 04

[ineedtofinishmyprojects]

1st, 13512, setting to 0 disables what little ESP there is in these trucks.
2nd p0700, worked on Taylor’s 05, didn’t work on my 04

OK, thanks for clearing that up!

[gstubbz]

Well a few updates,

I somehow came across a hemi G56 (which is a pretty rare trans) and had to have it so I picked it up.

But what info I really wanted to share was that I got the 05 5.7 MT computer with that G56, and all I did was plug it into the 03 truck and it started and runs just fine. However you get a P0052 code for Bank 2 O2 sensors (which the 03 trucks did not have) and in my case the brake and ABS light are lit up on the dash. Maybe I still need to repin something but that was just plugging it in not doing any modifications. HPTuners was also able to read the 05 computer just fine when I tried. I was hoping I could change the speedo for the larger 285 tires but doesn't look like I can with HPTuners on the dodge computer.

[ineedtofinishmyprojects]

Well a few updates,

I somehow came across a hemi G56 (which is a pretty rare trans) and had to have it so I picked it up.

But what info I really wanted to share was that I got the 05 5.7 MT computer with that G56, and all I did was plug it into the 03 truck and it started and runs just fine. However you get a P0052 code for Bank 2 O2 sensors (which the 03 trucks did not have) and in my case the brake and ABS light are lit up on the dash. Maybe I still need to repin something but that was just plugging it in not doing any modifications. HPTuners was also able to read the 05 computer just fine when I tried. I was hoping I could change the speedo for the larger 285 tires but doesn't look like I can with HPTuners on the dodge computer.

I'm about to take on this swap this weekend, we will see how it goes...


I never saw the last comment you made, you need this link to see the instructions on how to re-pin your connectors for the 05 computer...

https://www.hemitruckclub.com/thread...&sortby=oldest