So when removing the headers of the truck (the collector plate came off the header side, so I'm removing the header and the plate to repair out of the truck), I found that the exhaust had been double gastketed. I asked my neighbor about it (the one I got the truck from) and he said that it was a truck they used to use when installing cheap headers. Now, I kinda understand the thinking behind it, but does it really hold any merit? Or if I go and do the same when I put it back together, am I just wasting money? I know a lot of old-school tricks are still used for a reason- they work. But there are some that were just mis-conceptions. Just trying to sort out fact from fiction.

 

If you have the FE engine, there might be some "warping" of the exhaust flanges.Try checking with a straight edge. Thus the double gasket Some of the header manuf. make a better designed gasket for headers.

 

Yes...there's the dead-soft copper gaskets that compress and form to the imperfections of the head and header flange:

http://www.summitracing.com/parts/MRG-7164/

A bit pricey, but a good product.

They also have the three-hole collector gaskets.

 

Just replaced a set and used double gaskets. Another trick is soak them in water for about 20 mins before installing. They will form themselves better and dry soon as you run the engine.

 

I had headers installed at the end of the restoration on my 360 by some mechanics who claimed to be very fussy about header leaks. They bougth special bolts with retaining clips, etc.

Result - headers leaked like crazy. I pulled the 360 and dropped in a 410, so had a chance to do the headers again. I pulled them out when the engine was out and re-bent all the flanges that the original yahoos had bent by over torquing the bolts (by the way, the clips were a pain and I bent them all taking them off and tossed them). The header gaskets were on upside down, in some cases the weld bead on the header (this is the raised area on the header flange that forms the seal surface to the head) had missed the gasket entirely in some spots so the gasket never had a chance to work. Because the yahoos had installed the gasket wrong they then over tightened everything bending the flanges.

I considered the fancy metal gaskets but the vendor claimed to order them but never called so I assume he didn't. On installation day I had two sets of gaskets, we had bent the flanges straight again, and we put them doubled, in the right way, and with a reasonable amount of torque, they went on and have not leaked in a year, so no harm in using two gaskets per side.

The problem (I think) is that the FEs - with a few exceptions for some of the HiPo heads - only have one bolt at top and bottom, so it is not easy to get a solid seat.

 

So it appears that I have gotten the same info from this forum and the cougar forum i also frequent, and what I think I'm going to do is check the flanges (and yes, only 2 bolts per flange), straighten them if needed, and go with a set of copper gaskets. I'm not sure what gaskets were used before, but they basically crumbled when I pulled the header off the passenger side, and I am trying to avoid a repeat performance of that.

So I will check and true up all mating surfaces, get a set of copper gaskets, and make sure they are installed correctly. thanks for the info.