Any idea what that car weighs ? You'll find that there is more then just weight difference in the hardtail and suspended cars, them shocks do slow things down. I think the heads will be some what a limiting factor here. My 548 CI @ 2011lbs with dart 355s would run low 7.7's all day without leaning on it with single carb. There is a lot of things that will make or break this combo, rim/tire combo 16" rim will be .08 slower, conv will be key. Where you live will also make or break it, elevation has a to do with everything. If its a typical 4 link car @ weighs 1925lbs or so has a properly setup carb/conv/tire combo I think 7.6's is do able with them heads but not much more. This would be around me with slim to no good air to race in.