Ebay 1.8 manifold exhaust leak and questions
 

I recently bought an ebay 1.8 log manifold and have an exhaust leak (where it mates to engine). I'm assuming not all ebay manifold are perfectly flat and that may be why I have a leak. I also noticed there's no way to fit a nut on the center stud... hopefully that's not a big deal

I have a few questions:
1) Can I use basic hex nuts I pick up at hardware store as opposed to oem nuts on the studs? Or should I go buy oem nuts from the dealership? I wasn't sure if this was critical
2) My ebay manifold came with it's own single layer thick gasket. I wasn't sure if these sucked, or not. I still have my oem 3 layer gasket and might consider using that instead.
3) Have you had experiences where ebay manifolds are not perfectly flat and need machined flat from a machine shop?
4) Should I add orange copper gasket maker to ensure no exhaust leak?

Thanks

https://cimg4.ibsrv.net/gimg/www.mia...5dc5e89ef5.jpg

Which Ebay manifold did u use? If it's the same one I did then center nut can be installed from underneath before turbo is installed. I used new factory gasket and no leaks so far. Fingers crossed...

1) You can, but expect them to back out periodically because of heat expansion. Be prepared to re-tighten them every 1000 miles, or so. Get some high-strength flange nuts w/ serrated backs for better results. Grainger, or McMaster-Carr are good sources for that.
2) Get a replacement stock gasket, usually the single layer ones are junk.
3) Yes, often not flat. Check with a straight-edge. If it's not too bad, you might be able to correct it with some sandpaper, a flat surface and about 2 hours out of your day (or take it to a shop and have it milled).
4) You can, but I'd expect that to burn off in no time flat unless you have access to some extra-whoopie, super-duper, hi-temp gasket maker.

thank you guys!