340 Cam Change - Lunati vs. Comp.

IMO, from what I seen, I'm gonna guess that a 750 will out power the 650 by 10 - 15 HP at max!
The engine may want more CFM up top, but that doesn't allways workout in the street the way you may think or will tolerate. Some people can, IDK how you are. If it is an error, it's on the side of caution. You did say more street than strip.

I run the Air-Gap myself. If you run itin the cold, it'll take awhile to warm up and the carbs choke may very well close up on you reving the engine higher because it.....ta da.... got cold. LOL

(I live with that on my Cuda, but that engineis entirely different.)

OU812 can port your heads as needed. IF and When the time comes.