Can I use B or C body manifolds fore better flow on my sleeper GTS?

do you still run the overcenter spring with that clutch?

Yes sir, spring in place. The pp is rated at 2900lbs base which is totally opposite of the other cars I have ( 1200 lbs base sintered iron discs). The clutch tamer makes it work well. And don't be fooled by the IMO stupid high base pressure. It definitely slips moving out when you load it up. I can loosen it up with the clutch tamer enough that it will flare in every gear yet it never got away from the engine, even on nitrous. Mike at RAM clutches has been very helpful over the years and stands behind his products.