Seem to be a variety out there - plain old stock ones, vitron based, silicon based, and teflon based.

http://www.automotiverebuilder.com/ar/ar79842.htm - Discusses some options.

My head has a teflon type and I think they look like the "1611" below (not 100% sure). I'm still consuming oil and am now wondering if I might have seal problem on the stems. Also, there seem to be several construction methods for seals. The typical kind seem to have a metal barrel and some sort of spring that pulls the seal around the stem. Like this:



Then there are some that look more like this:



Looks like the head is coming out for a camshaft change so I thought now might be the time to consider what might be a good option. Of course, while it's apart I'll measure the valve deflection to check the guides.

Thoughts?

Thanks!