Streetable is all in opinion. My 360 is 11:1 KB107s, Shady Dell stage II Eddie heads, 258@.050 solid roller, 4500 converter, 3.91 gear, 830 Holley,full exhaust system, 3525lbs. It has been a best of 11.18@120.5 in good air and is very streetable in MY opinion. It will get 13-14mpg on the highway and has completed 3 drag weeks. I drive it to work, to run errands, to get groceries, it is streetable. It has a thumpy 1000rpm idle and it gets up on the converter to get moving but nothing that stops it from being street driven anywhere. Going down 20 cubes might move up the RPM range some but I don't see it having much of a negative effect on street driving.
Curious, what is the RPM at freeway cruise? Do I recall you're on 275/60/15's?? Thanks!
You know...This is a 4 year old thread you just 
I wouldn't hold my breath with that cuppa joe...