[mrsc3]

I have 2.5 inch alum pipes. It seems there are 2 options for the flanges. 1 inch and 1 and 3/8 inch. WHich one do I get?

 

[StickyRice]

The flange should only be one size, unless your talking about the height of the pipe thats attached to the flange.

 

[mrsc3]

Up for grabs we have a 1" Aluminum Flange for Blitz Blow off Valve, flange has 1" (25mm) Diamater, these can be used for OEM Installation or they can be welded as well on aluminum piping. I also have a flange with 1 3/8" (34mm) Diamater available in my eBay store.

I got this from ebay.