leaking headers!!!!

[aspenextreme]

i just cant get a set of headers to seal on this 360-can you guys help? i have a set of headman low dollar headers and im running copper gasket-still cant get them to seal. the leak seams to becoming from the bottom sides and ive tried everything i can think.
please help before i go back to exhaust manifolds.

[66Dart_GT]

I use high temp silicone (all silicone is high temp) Don't use the gaskets, place a liberal amount around each outlet and carefuly place the header on the head a install the bolts. I don't know how long it will work on the street, but it lasts all season for me!

good luck

jn

[ajmopar]

Someone on the board here suggested putting a couple of washers on the end bolts between the head and the flange and tightening the centre bolts to straighten or preload the flange and make it seal. Sounds logical to me. (remove the washers and put in a new gasket and when you tighten it up, start from the centre bolts and work outward).

[dwc43]

We always use the stock type parts house gaskets that look like paper on one side and metal on the back. We get two sets and glue them together with the red high temp rtv and only need on set all season for our race cars.

[FASTDARTCHESTER]

I had the same problem and picked up a set of Mr Gasket header gaskets. They are nice and thick and seem to be made of a high temp rubber reinforced with a steel mesh underneath. Won't fire the engine until next weekend so I'l let you know.

Oh, it seems like they compress nicely too.

[340duster1]

What type of heads are you installing these on? Are they magnums? One thing you can do is take the headers off and file the flange flat as it is likely warped. (If you are install them on magnums there is a port match issue)

[aspenextreme]

sorry guys i should have given more in fo, but i was too drunk to type last night. the motor is a 75 360, the heads are 79 vintage 360(jb welded those little holes shut). and the body is a 1979 aspen.the car is running 10.1 pistons and the heads were dished out to 2.02, but no porting. i had the heads milled on the header side just to make sure it was straight. this thing is leaking like a pig and its rather embaressing. please help.

[cuda66273]

Cometic has probably the best header gasket made.....I had the same problem with my super comps...this year I used a set of Cometics and the problem is solved no more leaks.

They run about $21 a set.

[340duster1]

Make sure the headers are not touching the block or the frame if they are it might be keeping the flanges from seating on the heads.