Evo o2 housing gasket

[92 EcLiPsE]

I was curious wiether to buy a 3in gasket or a 2.5in gasket for my evo o2 housing to downping connection. The housing is ported and the factory lip has been removed.

 

[chrisfrye]

I'm pretty sure it's 2 1/2" but not positive, especially depending how crazy you went with a porting a job. I have my evo III ported and used
http://www.slowboyracing.com/more.php?id=1874&

 

[MyBeatGSX]

Order it to whatever size the flange on your downpipe is. Most are 2.5", some are 3".

 

[blcknspo0ln]

I highly doubt you are going to get an evo o2 to a 3" port. Also, from how you are describing your port job, 2.5" is your best bet.