crazy gearing

well since the dart is not going to be my daily anymore and i am looking at my 90% complete 8.75 391 diff (-sg) i am thinking.

on randys gear it says that with a 28" tire and 4.56 gears i would be going 110mph @6100 rpm. which for now is fine.

can i get 4.10 to 4.56 gear for a 741 case?