I've got a 284-484 purple shaft in my 360, probably the older version since I built the motor in 1995 (but I'm not sure since I don't know when the newer version came out). My power brakes work fine, but I've got a vacuum reservoir. Without the reservoir, I don't think they would work well at all.

1974 'Cuda 360/TKO 1990 Ram Van 1998 Neon