230 and 250 inch engines are pretty much the same no matter what year they are. The main difference over the years was the head change to integrated exhaust manifold. All other heads are the same and swap freely. The 292 is the same basic engine with more stroke, they used the same heads as the smaller engines. If you have a good running engine, use it. The integrated heads work good when the exhaust isn't cracked, and in a light duty truck or van, it's likely OK. You won't gain HP or Power going to an older engine since the heads have the same design internally. The only advantage of older heads was the removable exhaust. If you are looking for an exhaust manifold, e-bay has new ones for John Deere tractors which used the 292 engine, same manifold trucks used.
As far as casting numbers go, the 230 and 250 can have the same numbers, you need to look at the piston tops to know for sure which engine it is. 250 used dished pistons, 230 had flat tops. Heads are all the same.
