I need Gasket Material Suggestions

I had ordered new exhaust, risers and gaskets from Skidim. While assembling yesterday, I noticed how "off" the riser gaskets were from the castings. Both on the manifolds and the risers. Nothing lined up perfectly and there was up to a 1/8" difference in some if not all the alignments. I completed the install, but after sleeping on it, I'm not cool with this situation.

I really feel the best way to do this is to make my own riser gaskets. The difficulty on this task should be very low.

What gasket material does everyone recommend for this application? Should I go with a regular Fiber based material, Cork, Copper RTV or something else?

Thanks

Don't do it. easy job but too risky unless you have block off plates and fresh water cooling. One gasket failure and you have an 8 cylinder aquarium and it's all your fault. GLM is an after-market manifold company that actually makes very good gaskets. Order them today, have by Friday unless you have a local dealer who stocks these parts.
I dont care where you get them, just trying to help. Everything is different in FW boating West coast. I have 5 stores / shops in < 20 miles from my house where I could cash and carry those parts. Sorry.

Good luck and be careful. Check the manifolds and riser surfaces for flatness before assembling.

Just leave it. The tolerance does not have to be that precise for that application.

I pulled apart one of the risers today and amazingly it was pretty well aligned. I guess when it got squeezed down by the bolts...it sandwiched into place pretty well. I am going to pull these apart at the end of this season to see how its going and w2ill probably address any issues then. but for now I am going to move forward with the purchased gaskets.

Sparky Jay, I disagree. I think the tolerance in this are should be equal if not higher then other areas. there is a real high potential to get seepage back into 1 or more cylinders if the riser gasket fails. In a saltwater environment (which I am in) it's nearly expected that you need to replace the Exhaust Manifolds and Riser every 3-5 years. The "scaling" that you get on the inside of both parts will exacerbate the seepage and cause untold amounts of problems with rusting, corrosion and pitting.

baitkiller, I have to you credit on the suggestion for the GLM gasket. I did get a hold of one today and it is really well made. I am going to pull apart the riser again this weekend and check out the tolerances. I have a sneaky suspicion that its going to be a better match.