I have to be the negative one.. I say with that set up.. It will run a for sure low 11's I have a buddy with a heavier car (68 BEE )but has a nice 500 stroker in it. His best time is 11:73 Just my opinion..
The motor has been a 10.81@126mph in my dads 73 duster with 488 gears and 29.5x12.50x15 Slicks and a 3500-4000 stall..But I have 456 gears and 28x12.50x15 E/T Streets. I will have a 4000-4500 stall..My buddy went from 11.0-11.1s with 488s and he went down to 430s and he picked up to a best of 10.83..
Oh ya do you know how much your buddy's car weights..