So I received a batch of the NOS gaskets I was referring too before, the 8 hole t-stat cover gaskets. When I overlay this on top of the newer 9-hole covers, you can see where there are some inconsistencies to the cuts and how things line up.
This is what I was referring to in terms of leakage. Keep in mind the newer gaskets have some ‘play’ in the way they seat too, but no matter how you line them up there is less ‘meat’ in a couple of spots and I have observed leaking on the side and the bottom of these covers.
It should be noted too that the newer gaskets are not as thick, so even if the surfaces are flat (forget warped), they are more likely to leak because when you squash them down with the normal tightening of those cover screws they don’t ‘take up’ the sealing surfaces as well.
If you look at the close up picture, the bottom area may be difficult to see but there is a difference. The holes don’t line up the same either. They are off on a few orifices and you end up wallowing them out when you put the screws in.
Fleetwin and T2stroke were kind enough to hunt down the OEM PN to be 321387 FYI.
