*SHOULDN'T* be anything that requires machine work per say.
As far as I know, if the block is post '86(?) then it will have the bosses for the lifter hold down. They might not be drilled, or they might be drilled but not tapped. Either way it should be a fairly simple process.
I don't know how they handled the cam though...if there is a retainer at the front of the block, I've never seen that addressed.
I'd like to see one of the non-roller roller era blocks to see how easy it would be. (does that make sense? heh)