Which set of replacement lower intake manifold gaskets is everyone using now? Am about to do another one and am curious as to which set holds up best over time. Really don't want to do this again on the same truck.



Re-designed GM gaskets with integrated crush washers:





Victor-Reinz with metal frame:





Fel-Pro Problem Solver with metal frame and seemingly thicker sealing areas:





Obviously, all are superior to the factory plastic setup (don't even see why they still sell these):

Felpr what I use

felpro is all I will use, never heard of the victor ones before, they look decent though.

I use the fel pro on all of mine havn't had any trouble out of them.

Thanks, guys. I know from experience the Fel-Pros work well on the notorious Pontiac 3.1 engines, but I've not had a chance to use them on the L31s. Last time I did LIM gaskets on an L31 they were just replaced with new stock type, as no one had yet come out with an improved design (to my knowledge anyway, circa 2001). Good to hear they are holding up for all of you though. Fel-Pro it is.

http://www.pacificp.com/forum/viewtopic.php?t=8740&postdays=0&postorder=asc&start=0

Completely forgot about that thread or maybe never even saw it. Excellent. Thanks for posting that.

Well, just pulled the LIM off of the 99 Tahoe and the "updated" GM gaskets (seen in the first pic in my original post) with the metal crush sleeves had been installed. True, they do not crush and deform like the original design does, but I have to say I'm NOT impressed with these new designs either. A lot of oil leaking right past them, and the very narrow rubber sealing areas are hard, not compliant at all, as would be needed here. No wonder it has been sucking oil into the intake runners. With his being said, those metal-framed Victors above (second pic from the top) would not be a good choice either, as it appears the neoprene sealing surfaces are quite narrow and fragile, just like the GM gaskets. The only advantage to the Victors is the metal frame. Would probably behave similarly to these updated GM gaskets I just pulled out, I would imagine. I will say that the coolant crossover area seems to not be compromised as it is with the original designs. But, this lack of adequate intake runner sealing is unacceptable.

The verdict is in... DEFINITELY go with the full-metal Fel-Pro gaskets.

Ideally GM should have never removed the 2 center bolts on each side like the ols SBC had. I see quite a few of the origonal design gaskets drop in the center and start sucking oil as well as missfires and vaccum leaks