Anyone know about this sb head casting numbers???
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From: Lafayette, Louisiana
Anyone know about this sb head casting numbers??? This weekend we pull apart a motor that my dad had bought about 2 years ago. He never did anything with it till now. The guy my dad bought it from said it made about 500 hp he bulit it himself and he worked in a engine shop. Well it has some nice pieces in it comp cam rollers rockers 1.6 its a roller cam with 306 duration and some very big lobes, not sure about the lift. polished rods and some big dome pistons. The casting number on the heads are 3998993. All I know about them are they are from 1972-1973 with 75cc chambers the head have in them some 2.02/ 1.60 valves I checked with a dial caliper and there are ported. Thanks if you can help Nick
That casting number came from a 68-79. They came stock with 1.72/1.50 or 1.94/1.5 valves. They are 76 CC chambers stock, and flow 150.8 on the intake and 91.1 on the exhaust. In stock form they are pretty weak heads. They came on 115-175 HP motors. Personally I would ditch those heads and opt for some vortechs - good cheap power.
