R/T makes no diff, so never sweat that unless you are racing heads up... when lookin for a time, its all in the 60'. I'd love to see a 2.20 60' and that same following 1260 ft...you'd hit 13.8 w/o any trouble maybe even a high 6 or low 7. Practice and slippin the clutch is the trick, not dumping. Basicly you need to be like an auto tranny w/ a good stall, slip til its grippin then give it 100% pwr or full clutch disengagment, then effortless smooth shifts.
Nice job so far!