Solid Lifter Cam
Hi Jeff. I have a couple ideas. Stock 1970 bottom end that's been re-ringed? That's one problem when it comes to Top End power 'ring seal/leak down... But you know what really stands out and i have not read all these Pages, just half of the first page....is the tune. Your timing should be at least 20° if not 24 °. Your total timing should be anywhere from 28 to 32 degrees. Also..did we degree the cam straight up or 2 or 4 adv?
As for the less than ideal convertor/gear..when you don't have the right converter or the right gears ..what you end up with is very specific or limited RPM 'power moments' as I call them.. where you can feel the power or potential ...but you can't use it in your regular driving routine 'off the line or low range driving...but regardless, you know it's there.
The 650 isn't a deal breaker either, 650- 700cfm is what I'd use for that motor combo.
The heads should be great.
It's mostly tune...then gear and convertor...then some more tune for that change. Every combo knows what it likes.