Should be a simple kit to build yourself. 4.25 crank from Molnar, a set of 6.535 rods from most anyone and a set of 1.32 CH pistons from most anyone. Only real issue is that you need to figure out what dish/dome you need to make the compression ratio that you want. Not everyone sells a big enough dish to keep the the CR down for a pump gas motor. If it is a race motor then it is a little easier.