Don Terrill’s Speed-Talk

What's the deal with the two types of metal clad seals, bare metal inside or viton(FKM) coated inside?

I got the wrong seals for my current heads, well actually I got the wrong tool to cut the guides. Can't find it atm but pretty sure it was suppose to cut to .500 but they are .494-.495. So the comp 517-16 seals(bare metal inside) will just pull off the six .494 guides. The .495 guides a seal took some effort to press on with my hand but had to use a tool to remove it. Suppose I could use some sleeve retaining compound on the .494 guides but in my research I found an old speedtalk thread with a site that has seals with the viton inside. Does the viton inside make them fit a wider range of guide?

Also I know comp has a seal 506-16 for a .494 guide, I'd bet my tool was mixed up or just poor quality if I could find it.

Anyways I'd prefer to get ones that fit instead of lock the seal on there. Also prefer the non comp-cam ones cause they have a better deal if they would work , these are two that may work
https://ussealparts.com/vs-108v-50-packs.html
https://ussealparts.com/vs-107v-50-pack.html

Cool found a couple references in old speedtalk post to using green retaining compound on seals. Still not sure how easy it would be to remove them, as I've never used the stuff but I actually just bought some for another purpose.

Anyways I just ordered some seals so we'll see