The wider the lobe separation angle the less lope you have from overlap. The less lope the more vacuum. Stay in the area of a size or two up from stock and you should be fine. I run a 415/430 cam in my flat tappet engines and it has good bottom end and power throughout. Stock for a 350 flat tappet was a 390/410 cam and a 305 HO and Corvette 350 cam was a 403/415. So as you see I am about two sizes up from a stock cam. The next size up would be a 420/442 which is a little smaller than a L79 327 of 447/447 and a 350/350 at 450/460. The thing to remember is today most engines do not run over 4000 rpm very often, most engines are running a little over 2000 rpm in overdrive at about 70 anyhow so you need to keep the powerband of the cam down low.:money: