ok after the 2nd exhaust gasket blew at the base of cyl 4 i have taken the mainifold off and took it to the lcal exhaust shop.

He says it isnt getting enough clamping force on 1 corner and was true on the straight edge. Then he shows me on the laminate table its true lol. says doesnt need facing as its pretty good.

Piggy syays probably not true from when it was previously modded.

just wondering if i reinstall with my last gasket, is there a sealnt goo i can use.

have been told loctite copper max high temp or some crc product works a treat with the gaskets.

I know piggy tried sealing it with exhaust cement with not much luck.

any tips or porducts or advice? would like to get it finished on sunday before it keeps on raining here.

still dont believe the whole flange was flat. it might have been close but no way the whole thing was true

I've always used coper gasket sealent I think locktight makes it ....
It's designed for hi temp applications.
It's Awsome stuff I use it heaps

how thicks the flange of the headers? surface grind would do the trick if its thick enough?

Could you drill and tap an additionl stud in place to provide a little more clamping force?

Otherwise, would a copper gasket do the trick?

surface grind? obviously not by me with an angle grinder.

ive heard if its pretty close,not exact, the loctite or permatex ultra copper stuff in conjunction with a gasket usually does the trick, or does it have to be spot on flat?

i didnt have to use any sealant on my other L series and the extractors fitted fine, a different pair of extractors that hadnt been cut and shut like these. but those ones have blown out then gasket a number of times so i cant see how they can be flat and still do that. its not like L series have a problem of not having enough clamping on the extractors

pretty sure i'd even put a straight edge over them and seen that the number 4 flange was on a different angle to the rest

well held together when warming the car up, and then lasted a 5min drive before i parked it. figured its 2oom to epa tester, so hope it holds til after that. any longer will be a bonus

I have used high temp RTV sealant (the red stuff) on exhaust (and intake) flanges without gaskets successfully before.

Just don't use it if you have a O2 sensor as the fumes wreck 'em.

no o2 sensors, its a datsun, the copper one i got is o2 sensor safe, just incase i want to add a wide or narrow band 02 sensor later for a af guage