[steve25]

I take issue with that statement that Pontiac used positive seals on the intake guides of all 67 and up 4 bbl base line motors because I have never seen such.

I have disassembled at least 80 stock heads in my life between working at a machine shop and my own motors and I have never seen such and also not to mention that the Pontiac parts break down drawing don’t show any either!

The parts break down’s only show the valve stem o-ring oil seal as in this photo here.

Note item number 10.

[Kenth]

Originally Posted by steve25

I take issue with that statement that Pontiac used positive seals on the intake guides of all 67 and up 4 bbl base line motors because I have never seen such.

I have disassembled at least 80 stock heads in my life between working at a machine shop and my own motors and I have never seen such and also not to mention that the Pontiac parts break down drawing don’t show any either!

The parts break down’s only show the valve stem o-ring oil seal as in this photo here.

Note item number 10.

I wrote "high performance 4-barrel engines" NOT "4 bbl base line motors".
There is a difference.
And, your Pontiac illustration catalog picture shows an exhaust valve, exhaust valves did NOT use positive seals as i stated.
Also, take a look in the Parts&Accesories catalog group 0.308 and you´ll find #9790818 (positive) 8 seal, intake valve stem oil (w/retainer rings) for 1962-74 All engines. (As required for engines using them, of course!).

FWIW

[TRADERMIKE 2012]

Originally Posted by Kenth

I wrote "high performance 4-barrel engines" NOT "4 bbl base line motors".
There is a difference.
And, your Pontiac illustration catalog picture shows an exhaust valve, exhaust valves did NOT use positive seals as I stated.
Also, take a look in the Parts & Accessories catalog group 0.308 and you´ll find #9790818 (positive) 8 seal, intake valve stem oil (w/retainer rings) for 1962-74 All engines. (As required for engines using them, of course!).

FWIW

My 1967 428 ci HO YK code means Automatic/4bbl, I fit in that category? When we installed the 041 Cam, Johnson Lifters and HD Chrome moly Pushrods and new Oil pump and pan and Oil splash shields under the Valve covers, we noticed that the gasket set that came with this second-hand project included the
Valve seals in the opened box. So, we elected to use them, not being sure if we should or not, I guessed where to install them by seeing how they could only fit. Since the Exhaust Bosses were all cut to fit the Black metal band ones, positive seal I think there called, they got them. The Umbrella seals fit over the Intake Valve Bosses, therefore they landed on top, where the shoe fits, so to say.

Note: The mechanic mentioned that he is installing "o"-rings for the valve stems and he is milling the 8 remaining un-cut Bosses for the same positive seals as the Exhaust contain. This way they can't be carried off the Boss by the Intake Valve stems. Also, since my roommate performed the removal of the Springs, using compressed air into each Cylinder outside and out of my view, installing the new Valve stem guides, only he remembers what type of old seals that he removed, I can't ask him at this late hour.