The 261 being the big brother of the 235 would be my choice, lots of stock and performance parts around. The most popular GMCs for building were the 270 and 302s, now getting tough to find parts for. The only GMC I owned had a cracked head and all the replacement heads I found were also cracked and that was 20 years ago.

Have some local Inliners building the GMCs, they also have collected many parts motors over many years.


It's easier to get forgiveness than permission!
1946 1/2-Ton Chevy
1953 Chevy 3/4-ton Factory Stakebed