[MescaBug]

Howdy,

Got a new set of intake gasket from Felpro. Cant remember the exact model number. The old gaskets were falling apart and causing a leak.

Bolt holes lines up between intake, gaskets and heads, but see how much of the gasket is protruding above the intake line? I'm not even sure if the runners will seal properly

Is this normal? I think something would be wrong if the holes wouldnt line up but it lines up just fine.

Any help/advices would be greatly appreciated.
Thx!

EDIT: Bought these because it comes with the crossover blockoff. I guess they are the Felpro 1233?

[77 TRASHCAN]

Use a pencil or sharpie and draw a line where the intake sits on the gasket. Then remove the intake, lay the gasket on the intake to line up with the drawn lines, to see where you are.
If you are concerned with the opening at the heat riser, you may have the wrong gasket set.

What year heads and what year intake do you have???

Part number on gasket set???

[MescaBug]

72' intake and heads (485912, 7K3 heads).

I read that the Felpro 1233 is often used with aftermarket and HO aluminum intakes, which have taller ports.. Any thuth to this?

[Bruce Meyer]

Originally Posted by MescaBug

72' intake and heads (485912, 7K3 heads).

I read that the Felpro 1233 is often used with aftermarket and HO aluminum intakes, which have taller ports.. Any thuth to this?

Yes. The port size is suited for RAIV ports.

[MescaBug]

That would explain it then. I'll draw a line and see how much is protruding above the runners.

[67GTONUT]

That gasket set should come with 2 sets of inserts for those center ports....

Full block off and a set to use with the smaller height...

or you can buy the FelPro MS9980

https://www.amazon.com/dp/B000C2ALLO...v_ov_lig_dp_it

[chiphead]

I've found that the 1233s are a tall gasket. The port openings are taller, but the overall height of the gasket is taller too. On my engine, they hit the valley pan gasket and didn't want to lay down. I had to trim the gasket back to fit properly. Of course I've got 670s millled about .020", RPM intake ports matched to the 1233s, block decked and valley pan modified to clear intake.

The RPM has more meat in the flange area than some iron intakes. There is also the risk of early intake/ later head exhaust crossover mismatch with the '72-newer heads. The correct gasket is required to seal it off.

Verify the gasket is laying flat on the head surface and the plastic bolt hole inserts are in place. You may need the standard (non RAIV) pontiac intake gasket correct for the heads you're using.

[77 TRASHCAN]

Unless you have your exhaust crossovers filled, those gaskets will likely leak, even with the crossover blockoffs. Without the intake being seated on the tops of the crossover gasket, exhaust will likely leak at the tops if installed as in picture...if you decided to go ahead and use them...

[MescaBug]

I figured out what the problem was. By the way, that's a cam swap project, so I thought I'd install new gaskets and all. I bought a Felpro complete gasket kit. I used the cork gasket under the valley pan, which I never do (usually just RTV). The gasket was protruding outside the valley pan lips, so the intake gaskets was sitting on it. Took the cork gasket out of there.

My bad. The 1233 is taller, but all the runners are way below the gasket. The crossover blockoffs still protrudes over the intake line, but its much better than it was. I'll give it a shot. Will change to Mr. Gasket 502G if it leaks.

Thanks for the comments.