I am in the final stages of what I hope will not have been a huge waste of good money. I have an "89" Silverado 3/4 Ton HD with 350 TBI and 400 Turbo automatic. I put 225K miles on the truck, and needless to say she was beginning to get a bit tired. Instead of dropping 35K on a new truck, I decided to give my truck a complete transplant. Starting with a Stroker 383 w/ 4 bolt mains and rebuilt original style TBI heads. Throttle body and intake are bored out to 50mm, and with an adjustable pressure regulator installed in the TB, and a new high volume fuel pump in the fuel tank, it's supposed to be capable of flowing 750 CFM. A complete Roller Camshaft, Lifters, and Rocker Arms assembly. Heddman long tube headers with 3" dual exhaust. A custom ECM Chip burned by Harris Performance TBI Chips. The software claims this setup will produce 373HP / 483 LB Torque.
The Turbo 400 (3 speed / no overdrive) was completely rebuilt and modified by Mad Dog Transmissions to handle the extra horse power. The current rear gears are 3.73's and I am considering changing them out for 4.10's. And I am also installing an electronic Detroit Locker in the rear.
I have about $8,500 invested in this build. I know, I know... that's a lot of money to sinck into an "89". But for me, if all goes well, it will have been worth it. That is a big IF though :(