6BTM or locked out timing?

If you can post up some info on the 6btassmBeavis, we'll be better prepared to answer your question. I never heard of the damn thing.
It’s an MSD box that has a boost reference line. You can adjust a dial to remove X degrees of timing per pound of boost. That way it drives completely normal when you’re not into the boost. I used mine with my stock electronic Mopar distributor in the 318. Don’t see why it wouldn’t work with a slant six dizzy.