It's less about performance gain and more I'm kinda tired of the constant leaks and they are so much cheaper to replace.
I recently rebuilt the engine, and things were fine again for a little bit and now it's spitting gasses at multiple points. I just don't feel that the mating surfaces are matched any longer. I have pulled them and reinstalled them with new gaskets plenty of times. With the headers, there's less surface area that comes in contact with the block and IMO less excess material to restrict the compressing of the gasket. But I could be wrong. Eh.Used factory manifolds are on ebay for $50.00 each, and i'm sure tillery has a pile for a good price. Are your leaks at the exhaust ports or the y-pipe?
That guy won't give out any info on what he's done to his truck except that completely bonkers hydrogen fuel setup he swears by and that Jesus will save you from the plague.Why not stay with factory manifolds? Headers are hard to get sealed and a lot rust or warp, not counting clearance issues. It's a lot of headache for very little power. I say this with years of experience in a shop repairing exhaust. Not trying to knock on you, if you have a cam and heads that require more flow then by all means...
There is this guy
Squared as in machined?Have you squared up your manifolds? I would before I re installed them. You could then get them ceramic coated and call it good. The manifolds are actually not a bad design. The factory Y pipe leaves a lot to be desired. The one on my 94 had so many restrictions. It really couldn’t have been worse. Not sure if they are all that way or I just got a special Monday morning version.