: 67 DeVille 429 Exhaust Manifold Gaskets

Georgia Johnny
08-27-04, 03:32 PM
Car runs great but I can't get the (factory spec) exh manifold gaskets to last more than about 5k miles. Can't seem to locate any "tougher / header-type"
gaskets that'll fit. Don't mind spending a few extra $$ on copper or aluminum gaskets - anyone know who or how such a set could be "custom made" ?

All other advice also welcomed. Thanx, GaJ

03-01-05, 06:06 PM
I have the exact same problem with my 1970 DeVille 472 engine. Please , if you locate any heavy duty gaskets please email me the info zolaray25@hotmail.com Thanks, George

03-01-05, 07:29 PM
Have you tried stacking two new oem exhaust gaskets together? Your exhaust manifolds may have warped from the heat over the years. Two gaskets stacked together would help fill any voids. You may also want to clean and torque the exhaust manifold bolts to 35 lb/ft during installation.

07-05-07, 03:04 PM
My thought is the manifold is warped. Pull it off and verify with a straight edge or have a machine shop do it for you.

08-16-07, 10:41 PM
I had same issue with my 429 ci, I had the heads decked, and talked my buddy into "decking" the manifolids. Never had a nother problem after that.

09-08-07, 07:44 PM
My '73 Cadillac had a cracked exhaust manifold. I found a replacement set, and after having them machined straight I painted them with Eastwood exhaust paint and had them installed w/o any gaskets, at the "suggestion" of my mechanic. No leaks yet. Question - did you have the bolts retorqued after a couple hundred miles?