More often than not the later blocks will fit the first gens, it's the early motors going in later cars where you usually have the issues. Always exceptions to the rule... and as Jim mentioned there are always ways around it if you do find an oddball...

I've found quite a few good candidates as of late. I know a few who part out Big cars and use them for Derby cars... they sell a good running complete motor for about $250. You just have to have the space to store em lol...

Brett!