Yep, draw through needs a carbon seal.
I have an old draw through setup off a 440 that was In a motor home, but that's a bit large for you.
If you could get one of the Buick setups with the TO3 (IIRC the others were rotomasters) and try a smaller turbine housing, you might get usefull boost.
IIRC Hot Rod had an article on a father and son that had turboed their small block in a vintage camaro, they said they were paying a couple hundred bucks for the turbos, they were supposed to be for an implement of some sort.
