[Thanks for previous responses on the blocker rod...]

Currently building a 727 for 99% street use and automatic shift ('72 Road Runner, 451 low-deck stroker, 550hp).
Trans will have:
- TransGo TF-2 kit (automatic shift)
- Early-style front servo with A&A springs
- 4.2 or 3.8 lever
- Rigid front band relined
- Typical clutch upgrades

How many return springs should I run on the front clutch piston? This '72 400 'hi-perf' trans had 9 originally. I keep reading about going to 12, but don't know if that is for very high line pressure, manual VB, etc. Any advice appreciated. Thanks.