Gas Mileage

What kind of gas mileage is the norm for a v8 maverick. My pal down the road has a 74 mav. with a slightly modified engine and he says he gets about 20 miles a gallon at 60 mph at 2500 rpms.

My h.o. 87 302 roller engine has a f-303 cam I think (purchased on ebay around $70) and an aluminum intake, headers, dual exaust, underdrive pulleys (serpintine belt system), Barry Grant road demon carb. and a 2 inch spacer.

I was wondering also what kind of heads the gt-40p heads are off an Explorer?

Thanks in advance for your input. I am 16 and need as much guidandce as possible because my father only knows so much about cars.

 

I started a thread on tis a while ago....
http://mmb.maverick.to/showthread.php?t=21585&highlight=gas+mileage

 

I used to get 22 if I drove decently, now I get 8. Preston

 

there are a lot of variables, but 20 on the highway can be fairly average. even two guys in the same car will get different mileage though just on how they cruise the pedal and accelerate to speed.