don't let anyone worry you about gas mileage. I have a supercharged 270 and get a solid 16 - 17 mpg on the high way and I like to stab it now and then. Also talked to a guy from northern WA. with a 302 with 3 carter Webers ( stove bolt eng. co. )and lots of other goodies, all in a 39 coupe. He said he was getting around 19 mpg and he was pulling a tear drop also. If I were you I would bump the comp. up a little 8.5 - 9.0. use a small port head if its just a cruiser. Headers and good carbs not the old stock dribblers. then hook it to an overdrive trans of some kind t-5 or 700r4. you'll have one nice driver that won't look like all the others. I really dig the old suburban's