Have to agree with 37 Caddy. I learned a long time ago that you don't hot rod your daily driver. Even if you did the 347 swap, I wouldn't start with a flat tappet block. There ought to be a plethora of late 5.0 roller blocks to start with, even in AK. I might build a 5.0 roller 331 and plop it into a Ranger or something like that.

Just because you own two flat tappet blocks isn't a good reason to start with them. Too many problems with available off-the-shelf oils these days to start with a flat tappet block in my opinion.