Roller Block Cams?

I used a Comp roller cam in a 91 360 block with Melling replacement roller lifters. Engine is still running strong.
I think these roller blocks may become sought after blocks. With what's going on with camshaft quality in the past few years.
Curious if the crate motors are based on the LA blocks or LA roller blocks or the magnum blocks.
But the la rollers are an inexpensive way to have roller lifters!