Anyone ever make a cut between the flanges on your headers to independatly seal them? I recently got a 454 out of a boat and the manifolds had cut on them, assuming to better seal? I thought this might be a good idea before I mount up my new headers. Thanx in advance.

My neighbor swears by cutting the flanges.

The best option I've found is to run beads of high temp RTV around all the exhaust ports, head and header side, of CHEAP paper gaskets, and bolt them on.

some people do them to cheap headers due to uneven surfaces, but good ones are usually thicker and even. it release stress that is for sure.

It won't hurt anything cutting the flanges. If you look at the big dollar headers they have individual port flanges. I cut mine and use stock manifold gaskets and have yet to have a leak. Install, bring up to temp then recheck the tightness of the bolts.

I always wondered why the flange was one piece in the first place. I suppose it's to simplify manufacturing and make sure the holes all line up on initial assembly.

I always wondered why the flange was one piece in the first place. I suppose it's to simplify manufacturing and make sure the holes all line up on initial assembly.

Ease of Mass production, that is about the only reason for a solid flange

My old Blackjack alumacoat headers came that way.

I cut all of mine. I had to cut one of the flanges for the temp sensor on my heads, so I just kept on going.

I figured it has to seal better without a flange being able to warp. I haven't put that many miles on yet but so far so good.

I cut mine... It didn't seem to make much difference, but I think they were a bit warped to begin with. Looks better though.

Cool, looks like I'll be cutting mine. Any suggestions on how to cut ceramic coated headers? Don't want the ceramic to break off.

i just put a set of heddman hedders on my 77 camaro. lots of the ceramic coating chiped off. i would say hack saw, but thats my opinion and im new to all of this. i dont really care that it chiped off because i know it will melt off anyway.