Which heads?

Haven't checked my 318 heads to see if they are the 302's. My 318 is a '85. I got it out of a Dodge truck thinking it would have the roller cam. NOPE! When I installed the intake it had flat tappets. I researched and learned that not all '85's had rollers. I wanted the roller for todays oils. 340 sized cam would be one that's a stock replacement or something around that .450 lift and 268 duration (advertised). Car is just a cruiser with the wife and kids, however, I will take it to the drag strip at least once a year. And, of course, a little horse'n around out of town, ya know?? Trying to keep my gas mileage too. Started at 20 mpg with the 2bbl, and ran 15.90's at 84 mph. The 4bbl has me down to 18 mpg and I don't want to go much less, if any. Haven't got an E.T slip with the 4bbl yet, but the car has more off line punch and pulls a little harder the whole way through.