My combo is similar but with better heads but less cam. 272.279 solid roller, Stage 6 heads, 850 Quickfuel carb, 12.1 CR on Av Gas since its the same price as normal fuel down here, I get 645 rwhp & gets my factory trim e body @ 3720lbs running 10.5@125mph. I could probably run faster with a bigger carb but I built this to race in our 11 zero class on the Friday night drags. When its colder & no track prep, 10.80s are the norm, just have to sandbag at the finish line.