I'll say 7 teens sorted out, it will need more carb IMHO. Don't let anyone fool you, the X-Celerator is a good intake. I went 7.20s in a 3240# Dart with a stock stroke 340 on pump gas with a hydraulic cam. The 3.91 gears will be fine, your motor should be a torque monster. I'd shift it around 5800- 6000 rpms if it were mine.