Scott:
I recently went thru this debate about turning my 95 Mustang GT into a P/S but after 2 months at looking at the rulebook, I ended up buying a 89 Mustang Coupe 5.0 to run in NHRA/IHRA Stock.
As I interrupt the IHRA rulebook:
* That TH 400 is not legal for P/S --Must be the trans that came from the factory with only a shift kit and convertor change.
Check out IHRA's rulebook (from the link below) for all the specs for P/S. It's pretty restricted, but I believe your SS would probably run o.k.
Good point on the TH400 Alan. Thanks for the reminder ... I knew that once upon a time. My old car had the 4L60E in it but this one has a nice Turbo Action with a good TC. That's funny that I can't run a TH400 but 60's stockers can run Metric transmissions. LOL Given that, since I have good parts and make nice HP numbers, I'll most likely do a forged 396'' motor and add more nitrous and shoot for the 9s with my 4100lb. tank.