360 build questions.

I actually PREFER the first seals you pictured. Nothing wrong with any of them though. I would have left well enough alone. You are over thinking it and wasting money, IMO.


Exhaust seals can actually be LEFT OFF and it will never hurt not one single thing. As long as oil is changed regularly and there is no sludge buildup you will never have not one single problem.

Where the problem arises is when people don't change the oil frequently enough. This causes sludge buildup which can affect oil drain back. If the oil gets high enough in the head, it "could" run over the exhaust valve guide and dribble down the valve stem into the cylinder and cause smoke on startup. All things in good shape, that will never happen.

Since there is not a vacuum on the exhaust side and only on the intake, oil cannot be sucked into the cylinder past the guide. LOTS of older engines never had exhaust seals right from the factory.

Want proof? Look at the early Hemi. When they are sitting in the engine bay, the tips of the exhaust valves point down. No way in the world is oil ever gonna run uphill and into the cylinder. The stems get plenty of splash lubrication.

Lots of engine builders leave exhaust seals off. I would not think anything of it for one single second.