Most Street driven Hemi's don't need anything bigger than a pair of 600 EB's, even big strokers, In your case you can likely go either way and be fine. That being said if ultimate HP is the goal the 750's have more potential, what would work best all boils down to your entire combo and what fuel needs your engine has. I think a worked over factory inline intake and a pair of well tuned 750's would probably give you what you are looking for, ask Dave what he thinks, he's about as good as they come when it comes to working with that setup. I build the clones on either size carb so the choice is yours.