FOR A 71 NOVA 350 comp cam about a 212 intake and 218 exhaust duration with a 454 lift
ok i got a pair of brand new vortec cast iron heads cast number is 12558060
and i also have a pair of used cast iron GM production heads casting number 3947041 (X) in decent condition about 10,000 miles on them ...i got the intakes and everything for both of set ups...which will give me more hp? and how much more...ESTIMATED
and how much are the GM production heads worth if i were to sell them?
