Get two turbos for a hot air turbo Buick. 1981 were hot air cars. I think some of the late 70's trans AMs were hot air as well.

You want to make big power but will never make it with your approach.
You could do a single 88 and blow thru and accomplish your goals.
You know how to make headers now and you ain't scared to spend the $$. I would think you would want the HP without the hassle.