[rodneym]

Varmit,
The SR engines are favored over the R versions by people very familiar with Roushs, like Lance Stander and Erick Voss.
When I was talking engines with them, they both suggested the SR version of the FE (99% street driving).
I went from a 402R in a SPF to a 468SRFE in my Kirkham, so the effect of torque was compounded a couple times (SB to BB, bigger displacement, lighter car) but still, the motor is very streetable and strong as a bull. But it doesn't have the legs of an R. I guess it depends on how often and how long you stay above 5.5k RPM.