Question on Viton valve stem seal?
 

I believe that the valve stem seals in my heads are showing some wear.
Slight oil buildup on back of intake valves and occasional puff at startup.
So got the valve compressor and dug in and was surprised both intake and exhaust valves
has an oil shield. Pulled one from an intake valve and took some measurements.
Valve Guides are already machined to .530 and have standard valves .340 with two grooves.
Valves feel snug when trying to wiggle any direction.

Would like to know what seal you would recommend and where to purchase.
I like the Positive Type Seal with the Metal Shell and spring on top.
Need to replace all 16.

Thanks

Gerry

I had positive seals on mine and they were too tight. as a small amount of oil needs to ride between the guide and stem. i ended up putting the orings back on and reinstalling the oil shields on the springs.

I prefer the seal you have pictured, and go with those if the inner spring size allows it. These are more forgiving and seem to conform better. I just did a set of 670 heads that someone in the past cut the guides down to .527 and the steel shell seals would slide on loose. I went with a set of .500" non-sided seals and they went on like they were made for the guide.

I just order mine out from Summit.