[NastyBuzzard]

Trying to ressurect the dead here... I have a 1987 GMC V1500 4x4 long bed, 350 TBI/700R4 combo. When I bought this truck 10 years ago it was a beast! It had bottom end power for days! All that low end torque was great, would spin tires and be all kinds of fun! Even after cat converter was clogged and it backfired and burnt up the rings it still had great power. Now its not even a hint of what it used to be.

This truck and I have been on a loooong ride and a few motors including a built 400hp carbed engine but I wanted to go back to stock.

Recently, I rebuilt an engine out of a 92 C1500. It was bored .030" over w/ flat top pistons. I put a vortec roller cam in it as well with stock 193 swirl port heads. I added longtube headers and a heated o2 sensor. Also rebuilt trans, new oem style torque converter, new tcc switch, added transgo shift kit w/ corvette servos. I also switched to electric fans from a new body style impala. TBI injector pod spacer and ultimate throttle body mod. Stock 7747 ecm w/ no tune.

Also due to having to replace transfer case, we got one out of a 91 blazer and swapped over the instrument cluster as well. So i have electric speedo with drac mod and all that already, I even swapped in a 5k tach from an older model chevy.

First started driving it, the truck had hardly any bottom end power, so I swapped from 3.08 gears to 3.42s and it didn't help much with a 32" tall tire. Nothing like the original engine was.

I can't seem to get this dang TBI setup to run correctly and have been fighting with it for over a year and havn't even got 10k miles on this setup. It has hardly any bottom end power, and is having an issue where it shifts around 45 into OD and locks tc up and drops to about 1250 rpms and has to struggle to get the rpms back up.

I have now found a 01 Silverado ext cab 5.3/4l60e 4x4 that I am trying to pickup for 1k. It is the whole truck minus bed, fenders, hood, and rad core support. It was abondoned at a buddys shop so they just started parting it out and are now looking to get rid of it. It cranks up and drives still and has around 150k miles on it.

So I guess I will be tossing the TBI for the LS vortec engine. I read this whole thread over the course of 3 days.

Also due to fuel tank switching valve failing about 6 monts ago I have a new one of those as well. Will it need to be replaced?

Any advice guys? Also, any issues you can foresee since my trucks 4x4? Also A/c will be one of my least worries but I may try to get that all working if I can.

I am looking for a good reliable setup that will get great mpgs and allow me to tow/haul decently. My playing in the mud days have been long gone. I even took the 4" lift off and have went back to stock height when I swapped the 3.42 gears front and rear.