RE: 48" Viper
I tried a B/S/T Texas cut SS 280 on my 51" Cobra with a stock Zen and the same tuned pipe, but 90° 3" header and it did not work well at all. Never could get it to hit the pipe with that big prop. I also tried a 6717/3 B/S (I did this prop myself and rounded the ears so that may be why it did not work well) and it had a hard time hooking and was lacking on the top end, Also ran a slightly modded x472 and it did not like that one either. I am running a 73mm Enforcer prop now and she runs maybe 45mph in 3-4" chop and gets on the pipe real nice, hooks well out of the hole too. I have no idea what pitch this prop is, or if it is even still available. I am going to try a 275 on it this next season and see how it does.