I am installing my exhaust now and i bought the exhaust used. The guy included the old gaskets but they are no good, the diameter of these gaskets are 2.5"...however when i measure the pipes themselves, they are only 2.25"...do i need to buy the 2.5" gaskets or will I be ok with a 2.25" gasket which is the actual diameter of the pipes themselves

 

It depends on how you are measuring the gasket for one thing. Inside diameter, outside diameter, on-center?
I am no mechanic, but what I would do is hold the gasket up to the flange and see if it lines up correctly.
Also, if the gasket is from the exhaust you bought, chances are it's the right size.

 

well the id of the new exhaust i bought is 2.25"...so technically a 2.25" gasket would fit the opening perfectly...

 

It will work fine but you'll be slightly restricted. The best fix is go to any good parts store and ask for Permatex Ultra Copper red silicone, part no. 101BR. You can thow away your gaskets with this stuff. You still can most likely get the 2.5 exhaust gaskets there also. That a pretty common diameter.

 

Stock reusable Gaskets have oval openings that are 44 mm X 31 mm. That is 1.70 X 1.23 in. or so. I dont know where you are getting 2.5 -2.25.

Lay the steel OEM on the header and make a judgment. Use Anti-Seize on your bolts/Nuts needless to say, but also brush down the steel OEM Gask. with it also

Also --torque in increments from center out

 

My bad--just relized you were talking collector side---No reason, if the material is there that a gasket cant be trimmed for ID


AND ---no reason on NA that you cant buy a sheet of exhaust gasket material and make your own

 

Back when I was searching franticly late one evening for 3" gaskets {with no luck} seems everyone had 2.5"s.

 

Can you elaborate on the 101BR?

 

Sorry that is the Permatex gasket maker part number on the tube. This stuff is fantastic high heat silicone that will not break down. You can use it in place of exhaust gaskets.

 

Thanks!!!!