Originally Posted by
merdith6
Back in the day when restrictors first showed up when I fell in love with Rb's and the p5 especially. I removed the insert. A few years ago I was talking to Mr. Hottinger the nova guy and he told me the p5's like lots of air so don't run anything small in it. If I remember correctly the p5 ran awesome without one now I run a 7.5 but yeah no insert runs great no doubt.
+1 The RB s7, SBK-01, and the first p5's ran great with no restrictors back in the day. You wont get the fuel milage that everyone else is getting, so I would start with the 8 and go from there.