I guess I was not clear. I had similar problems. What is your compression ratio? What is your initial and full timing and at what RPM? How much vacuum advance do you have?
I am running a 383 with good success. The 750 Holley should be appropriate. What differential gear do you have? What are your timingspecs? Compression?
I have built a 383 with aluminum heads, huydraulic roller, pertronix HEI, and Edelbrock quad. The usual chevy small block numbers don't work. Does anybody have any suggestions for initial timing and curve or carburetor set up?