Header Leak and Timing Help

[al2ride]

My headers were leaking and when I pulled them the gasket was burned through on the bottom of cylinders 3 and 4. I installed a new gasket but can't seem to get them to seal. I've tried using two washers (3/8 and 1/2) to no avail. I've also cut some washers to make the difference in flanges since the intake manifold (Clifford) is thicker than the header flange, but still won't seal. Not sure what else I could do?

The second problem is that if I time it at around 12 degrees it runs kinda rough but if I put it past the last mark (guessing about 20 degrees or so) it runs better. It appears as if the timing plate is original so I'm not sure what's going on. I've also attached a vacuum gauge and can get best vacuum (highest and then backed off 2") when the crank mark is about 20 degrees. Not sure what else to do. The one thing I haven't tried is piston 1 all way to the top and check if the mark is on the TDC hole....any other ideas?

 

[Old Dog]

This may sound strange but try using some red high temp rtv on the gasket. put a nice even bead on and let it set for awhile before you tighten the bolts, like you do with valve covers. some guys don't even use a gasket just the rtv.

the timing could be a couple things, could be the wrong cover or the wrong balancer, ya never know what someone has changed.
The balancer can also slip on it's self (the rubber in the middle).
If it runs good and doesn't ping I'd run it where it likes it.

 

[73CJ]

Does it have a non-stock cam?

Usually gotta run more advance with a cam.

 

[al2ride]

This may sound strange but try using some red high temp rtv on the gasket. put a nice even bead on and let it set for awhile before you tighten the bolts, like you do with valve covers. some guys don't even use a gasket just the rtv.

the timing could be a couple things, could be the wrong cover or the wrong balancer, ya never know what someone has changed.
The balancer can also slip on it's self (the rubber in the middle).
If it runs good and doesn't ping I'd run it where it likes it.

I went and got another gasket and installed it with red rtv. I removed the power steering pump to be able to pull the headers all the way back and presented the gasket against it. Well, the gasket is too elongated for cylinders 3 and 4. In other words, for those two cylinders the header opening is smaller than the gasket opening and that's why they have always leaked. Whomever installed that header must have gotten the wrong headers and I'm sure they leaked since day one. It looks like I'll have to get a new set of headers to cure the problem. If I would have known I wouldn't have bought that brand new holley and I would have bought an OEM intake, carb, and exhaust.

 

[al2ride]

Does it have a non-stock cam?

Usually gotta run more advance with a cam.

Not sure what is has. I bought it from a guy that had it for a month or so and the guy he bought it from said it had an 82 engine...but in fact is a 78. I just timed it by ear...once I get the exhaust ironed out I'll retune it to see where it likes it best.