The 1947 - Present Chevrolet & GMC Truck Message Board Network

Hi Everyone,

I've had my 1972 C20 for a few years now, and recently just completed an engine swap to give it a bit more get up and go. It started life as a factory A/C 402 big block truck with TH400 and Dana 60 limited slip rear, and was pretty much a survivor when I bought it.

The engine swap project involved some front end sheet metal replacement also, plus a full re-spray under hood. Replaced were both inner fenders, the passenger side was completely rotted due to battery acid leakage, as was the radiator core support which I also replaced. Same for the passenger side fender. New wiring harnesses replaced all the old, worn-out stuff.

For the engine, I'd always wanted to build a large inch BB Chevy so started out with a Dart Big M block with 4.5 inch bore. A Callies forged crank and rods with 4.25 stroke gave 540 cubic inches. Wiseco forged pistons with 15cc domes and Hastings rings gave 10.8:1 compression, so 93 octane is a must. Brodix RaceRite heads with 2.3" intake and 1.88 exhaust valves allow the engine to breath freely. A Howards mechanical roller cam pushes the valve springs close to their rated limit and Scorpion roller rockers transmit the lift. The engine is topped off with a Victor Jr. intake and AED 1000 cfm carb. An Accel HEI provides the spark and Hedman 2"' primary headers feed the exhaust back to dual 3" exhaust.

The swap was done in the height of the Austin summer so many days of 100 degree-plus labor were involved. Now I'm just enjoying driving it until I tackle the next project - refitting the A/C and getting it working. I'll post separately about that as I'm looking for any expertise and advise I can get.

It's great to be joining a community of like-minded enthusiasts, I look forward to sharing stories, knowledge and tips and tricks with you!