Thinking of swapping in a 351

[RedElvis]

Hey guys. I'm new to the GMC crowd. Bought a '66 (with 65 letters in the grille) from a friend that came with a 250 straight six.. It runs great.. Found out it's a rebuilt engine from a 74 GMC truck.. probably 18,000 miles now? Anyway, I'm thinking of buying a 351 with manual bell housing that's in good running condition.. What else would I need to do the conversion? My truck has a 3 on the tree and I'd like to keep it that way. I just tightened up the shifter linkage and it works like butter now.. Do I need new perches for the engine? Anything different about the shift mountings?

[bigblockv6]

You'll definitely need the frame mounted motor mount brackets that are specific to the V6 and hopefully your 351 already has the engine mount brackets as well. You also will experience the front coil springs will not be up to the extra weight of the V6 which will cause the front end to sit lower.