any recommendations? 70 chevelle, 454, super t 10, 4.10 gears

Not many choices, Lakewood and McLeod as far as I know. Lakewood has sort of been the standard for many many years.

lakewood sounds good. how does it get installed? does it go under the bell housing?

It replaces the bell housing

Why doesn't someone make a blanket for the bellhousing, like Kevlar or something ?

good question