Head help....

Ok, Dart Sport 408, small valve jheads, air gap intake, Dougs headers, 484 lift/ 279 comp cam, 750 Edelbrock carb, Revinator box, 2500 Hughes converter, Cheetah valve body in 904, and 8.75 with 3.73 sure grip.
So I built this car to mostly run to shows and work but wanted it to be fun at the track. I finally ran it for the first time last weekend and was very happy with a 7.96 in the 1/8 with a 1.73 60 ft. This is all steel, full tank of gas, and even the spare tire. I haven't done much with fine tuning yet but that will come
My question is how much do I really stand to gain with a set of say Edelbrock heads over my small valve jheads? My over all goal at this point would be to run A little faster time and keep it consistent. I'm thinking I would like to stay with the same cam because it's very street able and really unassuming. Thanks