Small Block Header port design and gasket area problem

I posted this in the Q&A section but it might be better suited over here. I picked up a set of Summit Brand 1 5/8" tube ceramic coated small block headers yesterday and when I got them home and out of the box I see that there's no way they'll seal up on my ported J heads. My ports are matched to the Felpro http://www.summitracing.com/parts/fel-ms90460 gaskets. The raised area around the port on the headers is too short on the bottom side of the port. The outside edge of that machined raised area on the header lands in the port on the head and well of course with no area on the head for it to match up against itll leak straight out. So my question is whose headers that Summit sells will work on my heads? Dougs maybe? But they dont say theyll fit an F-body but I would think a manual steering console shifted no torsion bar in the way 1979 Volare would have an easier time than say a 73 Dart getting them to fit. So have I screwed myself port matching to that gasket or is there a header thatll work? I saw in the Flowtech header reviews on Summits website Im not the first guy to run into this trouble apparently. The single review they had was leaking out the bottom of the port with no way to fix it.

You need to find a set of headers that are 1.75 inch tubes.

I know I am in the minority here but I can't see a use EVER for a 1 5/8 header. Ever.

Just to prove I'm incompetent I'm using 1 7/8 tube headers on a street/strip 340. I'd be scared but I've done it before.

Motor out to be able to handle bigger tubes. 494/510 Lunati static tested 9.25 to 1 compression Eddie RPM intake 3.55 gears 2800 stall 2.5" full exhaust on the street.

I've used both the 5935 & 5949 Mr.Gasket setups here...this is between a factory '596 head and Hooker #5901 Competition headers.

Both work fine, but they are slightly different sized, #5949 is for a slightly smaller port...not sure how they would seal up your existing combo though...you really would have to match them up I suppose and simply try them.

Looking at the gasket you referenced, the wide open center section will never seal against a header flange, I would want an isolated exhaust port...so from that perspective, how much of the inner port wall between the 2 exhaust ports did you remove? Or is there enough there that you can use one of the 5935 or 5949 gaskets?

No its not a gasket problem its the port of the cylinder head is bigger than the actual outside of the raised sealing area of the header on the outside ports (cylinders 1,2,7, and 8) at the bottom of them.

You might need something like a TTI that uses the whole flange to seal the gasket.