UPPER INTAKE MANIFOLD PLENUM GASKET baked on need help getting it off

[my1990300zx]

90 300zx non turbo UPPER INTAKE MANIFOLD PLENUM Gasket is baked on I need to replace it . I never in my years of working on a car run into this before . I mean on a steel head you can grind it off but this is Aluminum and scratches and need a level surface . I have tried razor blades every fine like that and this is baked on. Any solution or what can I do to get this off . thanks

[RubyRed300ZX]

It should be just a paper gasket with some light coating of a sealant like Permatex on one side if it's an OEM gasket. The plenum is, as you said, aluminum. Try soaking just the gasket by lightly spraying it with water or applying water with a sponge;then, use a solvent on the sealant.

[my1990300zx]

Hi =
All day today I have use CRC gasket remover and some old timer told me to try easy off oven cleaner some came off but most is really baked on for 25 years it did a number on this Plenum makes it impossible to get off . All I wanted to do was put a new on because i thought I had a vacuum leak now I wish I never started i should of put gasket seal or something its to late now,

[NolimitZ32]

The razor blade is a proven method, it'll take you a while to get the angle just right but once you have it you should be able to get it off fairly easy. If you are worried about scratches on the surface you could always use some cooper seal gasket spray on the plenum when you put everything back together.

[my1990300zx]

Yeah I have to do something I've work on cars all my life and this is ridiculous its baked on and etched the aluminum . Aluminum mars easily if it were steel I would of grind it off in minutes and I have been at this for freaking 4 hours ...thanks for helping

[NolimitZ32]

I guess I should've precursored waht I said by saying that the mating surface on mine has been scraped to hell and it seals just fine as long as you don't use something like a knife or screwdriver and gouge it, you'll be fine.

[my1990300zx]

Question when i do clean this up manifold i notice the new gasket has a coating and said to face down and for top which rests on the manifold is cooper seal is that better than aviation sealant ? thanks

[NolimitZ32]

I have no idea what aviation sealant is, the copper seal I am referring to is used on headgaskets when sealing a block, this stuff is sold at all autoparts stores.

[my1990300zx]

ok thanks