I like the 3.1 with the 4.10 gear combo but I really don’t like the electrical nightmares I’ve been having. I’m old school, I love carbs and will probably change if it keeps giving me problems. Right now I’ve replaced both injectors and rebuilt the distributor and replaced the computer, got too much invested to change now. When I get the heads back on I hope I won’t have anymore problems for a whileI had an 81 'Yota 4x4 with the 22r (carbed), swapped in a 20R. I've had a few Isuzu 2.6s and a few 2.3s. I prefer the Isuzu 4 bangers because of the timing belt. The Yota chain looks to be a bear to change.
I would stick with the GM V-6. Unless you go old school carb change, ANYTHING is going to be an electronic nightmare. You would also have bell housing / mount, radiator / oil pan clearance issues
I know but I’ve just got to get it put back together and see what happensYou can install a non-computer-controlled distributor and use an adapter to mount a Holley 350 or 500 CFM carb atop your stock manifold.
'82 S-10 non-California distributor:
So there's your backup plan! Hopefully you won't have to do that, the GM TBI system is actually pretty good when it's working properly.