Can someone reccomend a drop in viton or teflon valve seal for a big block chevy? Specifically a Gen 6 crate engine (454HO). I want to try and install improved valve seals on my engine to see if I can keep from having to change my engine again. I would also love to find a drop in valve spring for the 502HO cam I installed. It pulls ok but I think it could rev higher. I don't think the bottom end would ever blow up as it does not have enough valve spring to spin it that high. Thanks

Dave

Are the valve stems bosses cut for the PC seals already?

Dave,
I do think the tops of the guides on those heads are machined for seals, I will see if I have a set I can look at. If they are not machined, there will not be a "drop in" seal like you want.

As far as the springs go, what rpm is it turning to now and how far would you like to see it go ? Which 502HO cam do you actually have, there are a couple of different ones. I have used the 924 Comp springs on several 502 marine engines, but they dont usually turn the rpms of a car.

Dave,
Just walked back and found a set of Gen6 heads to look at. They are NOT machined for seals, so the only way you can put a positive seal on them is to pull the heads, take them apart and machine the guides for the seals.
You might have to do this anyway if you want to upgrade the springs to a double spring like the Comp 924, because the stock umbrella seal is not going to fit inside a double spring :(

You need to PM Vince [69-CHVL]. I know he has done both a seal and spring upgrade on stock HO rec port heads.

Thanks for the replies. I always thought it was kind of weird that they don't make a drop in seal and we are forced to adapt something else. I am not going to take the engine apart since it is still under warranty. What are the best stock replacement valve seals available? I do notice that the engine smokes more after de-acceleration and I thought I would run it a little hard to see if that makes any difference. I am definitely not gonna hold my breath.