SBC heads with weird valve seals
 

hello all

I bought a 1986 GMC K15 which has a mexican reproduction 350 which was rebuild recently

after inspecting the heads I found no valve seals and they won't accept regular 350 valve seals

I've tried many types and I found a set of stock 454 Umbrella style seals that fits perfictly

http://static.summitracing.com/globa...a-504-16_w.jpg

but after mounting the springs I found that they touch the seals even when uncompressed


what should I do ?
Replace the springs with something bigger ( wider ) ? stock? aftermarket?
try other seals ?

thanks

Regular 350 SBC valve seals are just "O" rings. The umbrella type seal you show usually requies the valve stem boss to be machined.

Vince

most 350s I have seen have both O-rings + umbrellas

this engine only have the O-rings but it is burning some oil

http://static.summitracing.com/globa...cca-501-16.jpg

so is it enough to use the O-rings only ?

GM has been doing it for 50+ years.

Vince

positive stop viton seals is what most engine builders recommend,
summit has them and shows a picture of them.

The stock o rings will work fine if the stock oil sheild is there. You have to compress the spring then install the o'ring then the locks. If you put the o'rings on first they won't work.