welcome to the garage Steve, and good luck with the project!
if the truck originally had that V8 in it, the vin number will start with a V, otherwise it had a 235 inline 6 .... in 55 the V8 would have been a 265, and a quick ID for that is no oil filter, otherwise as tango said, get the block casting numbers, and also see if there's a number stamped on a 'ledge' pass side front at the bottom of the head, there's folks here who can decode those for you
Bill
