Thanks to all for the info. My Duster already has 225 +.030, 318 valves, 340 springs, block cut .060 and '76 2bbl intake and exhaust. I've seen the 4bbl setup sold by Clifford and may end up with one, but one of the old mags had a twin 2bbl setup shown. Don't remember performance data, loved the looks! Can't find perf. info on hyperpak intake, like the looks from a perf standpoint. Started out with original 340 car in the '70's, bought this one to play with. Had 6, changed to 360; handles better with my stiff suspension with a 6.