Quick one here guys.........
Burnt out the exhaust manifold gasket on my L98 with hedders........(Stock Heads)
What size is the exhaust port for the purpose of buying new gaskets (COPPER ONES!!!)
1.50" Round?
1.63" Round?
1.45" x 1.48" Square?
1.45" x 1.55" Square?
I gotta ask cause there are so many different sizes out there?
Thanks in advance!
Chris!

 

Measure yours. Then you will buy the correct gasket.

 

The various header gaskets are for different size/shape headers. Get whichever ones fit your headers the best. We have no idea which ones those would be because you didn't tell us what kind of headers you have, so we can't even make a guess. All we can do is the dartboard thing. However, with stock heads, more than likely it will be one of the smaller sizes, probably the round ones.

A word of warning about the copper ones: they work great, but IF AND ONLY IF the sealing bead on them matches the header flange AND the head flange BOTH. If it doesn't, they WILL leak.

 

It should be close to a 1.5" square with rounded corners.

 

Crazy to say but I never did measure the diameter of the header flange opening but I did take pictures....... ( with nothing to relate the size to...though) They are hedman Elite's with 1 5/8 primaries long tubes same as the 68446's only thermal coated, I know I have the part # around here somewhere.... The only thing is the primaries are so close to the frame I can barely get a gasket in or out so I can't measure them!!!

 

Looks to me like you'd do best with something like the Mr G Ultra-Seal or the FelPro ones, with the small round hole.

Looks like any square hole ones you get, the corners of the hole may land ouside the sealing flange at the end of the primaries.

 

You could get close. Since you know the bolt center spacing, scaling the rest of the photo wouldn't be too difficult.