LA heads on Magnum Block

I know there is dozens of threads on here about this but I havn't really found what I am looking for.

I am considering putting a set of LA heads on my magnum because I would like to get rid of the problematic cracking issues of the magnum heads. I do not know if mine are I have not had the heads off my engine.

I know the early magnums still had the oiling for the shaft style but how early? I have a 93 engine was built either early 93 or late 92 i would have to check.

I have a 89 or 90 roller cam in it would it be correct for oiling?

What else would be needed to do the swap besides la heads and custom pushrods?