Valve stem seals

I have a 89 Caprice with a 305. When I start the car after sitting it will smoke for a few seconds. I changed the intake seals with the positive lock style that came factory. Now it only does it sometimes so I would like to change the exhaust side. I put new orings on the exhaust stems when I did the intake side but I can't remember if the guides are machined like the intake side to accept the postive lock style. There is a high temp positive lock kit for the car from auto zone. Just wondering if anyone has done this or if anyone knows if the exhaust side guides are machined from factory. Just trying to avoid popping a spring off right now to check. If its not machined would an umbrella style work?

I've put umbrella seals on a 350 cu in before about the same age. I got them from a machine shop he had a drawer full of them.

There are aftermarket umbrella seal which should fit the guide bosses. If you really want to go through the trouble, that would be the method.

I've found that positive lock seals help for the intake valves, but aren't really needed on the exhaust side. On my engine (which was rebuilt around 300k miles ago), I use the Teflon positive lock seals on the intakes only, with the rubber O-rings on all 16 valves and I have found that this is more than sufficient. If you have a leakage issue involving the exhaust side, and the O-rings don't help when replaced, this is an indication of worn valve guides and at this point, even the umbrella seals won't help much.

Thanks for the input guys. I figured the guides are worn, I was just looking for a fix without having to pull the heads. The car is getting pretty worn from 20 Ohio winters and putting more money into it isn't the way I want to go. I just didn't want to look like "Uncle Buck" when I fire this thing up.:biggrin: