The Denali AWD truck snd the Chevy SS truck AWD may have some components that may fit. Its a viscous trnsfer case that is full time AWD. The new Trailblazer SS has it as well. If it can fit under a Trailblazer you may be able to get it to fit in a muscle car with some cutting and minor mods.

My 01 Denali truck has this. Its pretty impressive and can take quite a bit of abuse. Lingenfelter took a truck like mine and added a mild stall and some spray and ran low 12 in a 6000 lb truck.

Just last week a Trailblazer SS with a 402 and halfway decent size shot ran mid 10s at 130...its a dialy driver.

The trailblazer drivetrain would be awesome IMO.