1998 Chevy Blazer 4.3 with cam, tuning help

Hello! So I'm plenty familiar with tuning carb'd engines but with this fuel injected stuff I'm a bit lost.

I needed to replace the intake gaskets on my 1998 Blazer with the 4.3 so I pulled the thing out and replaced all the gaskets. But because I'm an idiot, I said, "hey, why not a cam?" So in went the Comp 260/266. Which also meant I had to change rockers, so it got 1.6:1. Also some shorty headers just for giggles.

So now it's running way lean according to the spark plugs and has a light load misfire when warmed up. Scanner shows the fuel trims around 20% if I'm remembering correctly from the last time I looked at it.

I have an MPVI2 now, where would be a good place to start dialing this thing in?

Disable the MAF sensor and start dialing in the VE table. Remember the black box only uses the secondary table when the MAF is disabled. Then turn the MAF sensor back on and tweak the MAF table.

I'm doing a 2003 S-10 P/U with a 4.3 as well. The long term plan is to LS swap it, but in the interim, I'm doing a custom grind cam and a set of long tube headers on the 4.3. I'll be following your progress.

What valve springs and retainers did you use with your cam?

I cammed my 2004 lu3 in my Silverado and did the tubing myself, I recommend watching goat rope garage?s GM gen 3 tuning videos on YouTube, if you have any questions feel free to ask. I?m no expert but I know my platform pretty well