I once had a 307 with 882 heads with 1.94/1.50 valves, altough it was stock it was a fairly good motor. A friend of mine had a 76' Camaro with 307, th350 trans, 10 inch 3500 stall converter. The 307 had a comp cams 292H magnum cam, 10 to 1 flat top pistons, a torker intake, (I think), 750 dp holley, stock HEI distributor, stock camel-hump 2.02 heads. The car had 4.56 gears, it ran mid to low 13's. In my opinion the 307 is a much better motor than a 305. If this is what you have, and you want to stay low budget, I say go for it! If I were you, I would build the 307 with your 882 heads with bowl porting and gasket matching, maybe an edelbrock rpm air-gap intake, 650 dp carb, 1 5/8 headers, comp cams XE268 cam, HEI distributor. Anyway, good luck in your 307 quest.