tdubis

Can I replace my header gaskets with the engine still in the car? Diver side, 455, 1971 Cutlass Supreme.

Thanks,

Tom

1969w3155

Yes, it should not be too much of a job, unless your bolts are rusted or the heads of them are stripped.

Lee_A

Technically, yes.

But, you MUST make sure that ALL the old gasket material is removed from both the header and the sealing face of the head.

Then, you should try to determine WHY the gasket blew - if everything is "right" the gasket should last many years.

If the gasket has been blown for a long time, but the car was driven anyway, there is a chance that a groove has been burned across the header or even the head. It will not seal if that is the case.

FelPro and Mr. Gasket both make steel-core, graphite covered header gaskets, which I have had excellent results with on a variety of motors. Coat each side of the gasket with a thin coat of Permatex UltraCopper RTV for an even better seal.

Lee

tdubis

Thanks for the reply! I am not sure why the gasket blew other than the car sat for awhile and when it was parked no leak and when I dusted the poor girl off she leaked. I am going to order some gaskets and RTV and give it a go. The bolts are pretty clean so I do not anticipate to much trouble getting them out, knock on wood. Again thanks for the help.

Tom

oldcutlass

After you install them, run the engine to operating temp. Then shut it off and retighten bolts!

OldsManNJ

I have been using REMFLEX header gaskets on my cars for a long time now - they are "crushable" gaskets and will seal some pretty major warps/scratches in a header flange. I changed both of mine on my 350 in under half an hour - I would imagine they can't be much more difficult to change out on a 455.