Between Mummert, Eaton, and Tim McMaster’s site you’ll find plenty of successful approaches to the rocker/cam oiling problem. The 239, and I think the 256, used a different front cover that mounted a smaller water pump. That’s one clue, but anything could have been changed. The cam bearings and distributor drive gear and oil pump drive are different. It’s probably not worth starting with one of those motors due to expense and limited parts. If it’s a real truck 292 with a steel crank, the cranks a very desirable item for building a stroked. Plenty of guys have y blocks in 32’s, it’s tight but you can plan ahead. The truck bell is a little deeper I think, but that’s what’s in my 32. Mine was modified to mount a TKO500. The granny low truck trans are pretty big and heavy. I had 3 or 4 at one point and couldn’t give them away. Depending on your setup, the rams horns might work, and they’re not bad manifolds. The 57 car manifolds (flat top) are decent, but the those tend to be pricey. I saw one car where a guy did some fancy work and got the rams horns to work with the car motor mounts, but it’s not a simple deal. The trucks used the front mount and ears on the bell housing. You should see that on the truck.