The back of the blocks are the same from 1954 to 1958, 331, 354 and 392 Hemis. That truck motor has a bunch of industrial parts that where designed to carry heavy loads at WOT for a long time, bigger valve stems, different cam and lifters,super low compression and probally soild lifters with adjustable rocker arm amd matching pushrods and so on Not a bad thing but not the same motor as the passenger car motors That is a big car, not many of them around, I would be tempted to throw a 6:71 blower on it with dual AFB and go cruising, probally work with the hood closed and no holes in the hood That should be a PowerFlyte 2 speed tranny with push buttons, correct? If not and it is a stick shift type fluid drive on the column the stock clutches won't take much abuse so be careful on burn outs