i had a bb in my truck, it used the same mounts as a 350. Bolted to the tranny no prob, but needed a new flexplate for the 454 i had, yours probably doesn't need this because a 396/402 are different. Needed special radiator hoses for the top and bottom, or trim to fit, whatever works for you, but there not the same. Wiring was the same as it had the same dizzy (hei) as the 350. You need a big block truck oil pan, as a car one wont work. Id upgrade the radiator to the biggest one they make for your truck. Headers are different, and hard to get a good set without having to cut the frame of the truck to clear. The bbc oil pressure sending unit threads into the side of the block by the oil filter instead of by the dizzy on a sbc. I would upgrade the fuel system with at least 3/8 hard line with a new fuel pump because my truck had 5/16 line that would not cut it for high rpms. Pretty straight forward swap. the th350 might cry for help after a bunch of torque romping starts or lots of miles, but should handle it ok as it came stock in my dad's 74 camper special behind a 454.
