My car has a header leak. Im getting some popping from the exhaust when I let my foot off the gas at speed. I have a magnum 360 in my 71 valiant. I used my out LA style header, but I have a leak on the #1 header tube. Im using LA style gaskets. Do you think using a magnum header gasket would help seal it better, and is thier any kind of a high temp sealent the could help. Any ideas?

I used a set of napa ultra seal header gasket and the high temp copper rtv

on both sides of gasket and letting it hang on a wire for 15 mins to cure some

instaled the gasket and header bolts just snuged up some,let sit over night,torqued the bolts down tight by hand

no leaks for about 3 yrs till I pulled the engine

this was a used set of headers and pitted on the flange and warped some

I used a flat file and smoothed the flange flat around the port

68 Dart 318 A body 73 k-frame...

I know what ya mean on tight fit and header leaks

I also removed the studs in the heads for ease of installation

good luck

Get a set of Remflex header gaskets.

Since Im running a Magnum head with LA headers which gasket would you use? Is it better to match the head or the header?

LA


Magnum

I've had decent luck with Percy's ultra seal header gaskets on 2 big blocks and a small block. Not sure if they are the same as the Napa Ultra seals or not. These gaskets are made of several layers of a soft aluminum material and, according to the package, reusable, but I've never had the headers back off on any of my trucks. They're around $25 a set, but worth it in my opinion. I've also used the paper ones that come with most headers but coated them with permatex ultra copper on both sides like previously suggested.

Most header leaks are fault of the headers.

Remove the header and inspect the gasket. Find the leak and study the sealing surface of the header.

5/16" flanges also make this a losing battle.

I wouldn't call them high dollar, but high quality. You can get them on Amazon.com for under $30 and usually with free shipping.
Jim

i had a set of hookers that leaked.it was suggested to cut the flange between the ports so that the header would bolt up flat to each port. this was on a bb, it did stop the leak. on another set of hookers there was no tube extending pass the flange, basically there was lip to push against the head. we used a mig welder to build up the lip so that it would push the gasket against the head, this worked also. if you do this you will probably have to lightly grind (i used a flat file) the weld to get it flat. use a straight edge, lay it across the weld and you can see what you have to do to get the lip even and flat to each other.