what exhaust valves are in a stock gen 6 502efi ? inconel or severe duty ?

Inconel made by Eaton. Not the best, but they are decent quality.

i'm buying a used set of heads and figured i'd re-valve them before install. do i need to go with inconel on a stock motor ?? or will manley stainless severe duty work ??

thanks

If the heads came off a gen 6 motor they should be Inconel exhaust valves. If your buying new valves, Definitly go with the Inconel for the exhaust. They take the heat better. Who ever does your valve job make sure the you get a seat with of .090 - .100 minium. It helps to transfer the heat.

You save some $$$ if you use the Ferrea super alloy's. They are similar to the Manley inconnels.
http://www.ferrea.com/

i think that is what came in my zz502/502 heads.

Forgot to mention. Also have new exhaust seats put in. They have a tendency to fall out.