How did people run double hump heads on 400's? Their 64cc chambers & need a lot more timing. I've seen several over the years with flat tops & double hump heads & run on 93 pump gas. what's the difference?
just so everyone knows. i already have the vortec heads. their not costing me a cent other than springs & having guides machined. that is the only reason i want to use them. FWIW, i took the exhaust valves out to check the seats to make sure their not the one's with the big seat that restricts flow & their not.
Last edited by 406 ss monte; 09-13-2008 at 08:08 PM.