CobraNV,
I can not tell you which to buy or even recommend one over the other, to each their own. I can tell you that I have a Roush 427R in my SPF and I could not be more satisfied. I have about 6000 street, track and strip miles on this motor without the first hickup. It runs 11:60s/125+mph 1/4 mile on Yoko Avids w/32lbs air pressure. It feels like a runaway freight train going down hill from off idle to rev limit. That's all I know.
