1970 383 or 1977 440?

well I don't know about that cam not working for you. I have that same cam in my 76 440 engine with 452 heads, 650 Eddy carb, Edelbrock intake running 3 :23 gears and I can turn the car around in the middle of the street on take off If I am not careful so for what it is worth. But if I had it to do over again, I may have went with a 383. my opinion, not much difference to me.