later

i asked the question as to what size are the valve stems on my
98 hp500s and got the responds of 3/8, and since no one else responded i quessed that to be correct, although in my searchs i keep coming up with 11/32, how about it some of you guy's that work on these things every day 3/8 or 11/32.

later

bobby daniels

3/8'S FOR SURE ALL i'VE SEEN ,ALOT
hope this helps

later

thank you

later

Dave F

I'm glad you backed me up bobby.

Merc stuff for the most part is standard GM. Standard GM valves are 3/8.

I know what I'm talking about (most of the time)

DAVE

bobby daniels

no problem any time I know yours is not an EFI but
most of the EFI's came with innconel exhaust which is a good idea

later

is that to say that the stock mercruiser valves on the 500hps are not inconel material on the exhaust side and stainless on the intake?
later

bobby daniels

Two years the 500's came with non innconel exhaust but I think merc wised up and now they all do ,
For what its worth I would run inconel exhaust ,good manley intakes and good springs and rockers and drive it and enjoy it ,the rockers (gold ) have weak axle bearings and make me nervious to use ove 200 hrs of normal use (normal) ,,good luck ,,,,,later ,
Bobby