TH350 Swap

[STR8BALLN]

I have searched but I am still unclear.

I have a 70 C-10 with a 5.3 and th350 411 PCM.

What do I need to do for the speedo signal?

Do I need to get something for the PCM to be able to read the speed?

Any other tips or links anyone would be willing to share?

[mightyquickz28]

Just typing this so you'll have an answer, much delayed, but answered
You can either use a GPS on your smart phone to tell you the speed and you can mentally note the RPM that is commensurate with that speed...
OR
You can buy a manual cable to electronic signal generator (Dakota brand makes the most widely known iteration)

After that, fire up your HP Tuner, click on 'speedo' and set your VSS P./Rev - Trans, your Gear Ratio/Tiresize, and your VSS pulses per mile. (Mind you, depending on your PCM type and transmission type, your parms in the speedo section may vary)
I *think* my 0411 still has the auto transmission segment. I set my variables to the following. I'll correlated it to my GPS and it's still 5mph slower than I'm really going, but with that in mind, it works out okay and I haven't had a speeding ticket yet


HARDWARE
_VSS P./TRANS = 7.0000

CALIBRATION
_GEAR RATIO AND TIRE SIZE
__Trans Revolutions/Mile = 411.8554 mi-1(not sure what the notation mi-1 stands for)
__Final drive = 3.08:1

SENSOR CALIBRATION
_VSS PULSES PER = (Mile) 15.000 mi-1

PCM OUTPUT CALIBRATION
_PULSE PER
__Mile = 4,000
__Mile - ABS = 128,000 mi-1

Be aware, with my settings like this , the Cruise control never works

Even though I've searched for months, I've never found anyone that said, "I've got a TH350 and these are the settings I used to get the speedo spot on". I hope someone will now see this thread and say, "Dave, Dave, Dave... That's not right. You need to set the values to ..." and give us the correct ones.