I'm looking to get aftermarket blow off valves for my (3rd gen) stock twins and am having a bit of trouble coming up with the ones i want that have bolt on adapters that will accomodate the ~20mm I.D. hose size that our stock valves use. The smallest i can seem to find (for the Turbo xs bovs, which are the ones i want...nevermind why) is a 25mm bov that is used to fit Jettas. They have kits to adapt to Dodge Stealth, 3000GT, 87-98 Supra, 99-01 WRX, Dodge SRT-4, Eclipse 1st gen, Eclipse 2nd gen, 91-95 MR2 Turbo, Nissan 200SX, Nissan 300ZX, pre-'98 WRX, Skyline GT-R, Skyline R32, Skyline R33, and even a Toyota Starlet Turbo (whatever the hell that is). I can't for the life of me find out if any of these equates to a simple ~20mm hose adapter. Does anyone have any clue about this? I'm going to be making some calls to find out, but i find it hard to believe than anyone i talk to will really be able to help me...or willing to. So if anyone is familiar with these cars and their bov fitments, it would be of great assistance if you could help me out here.

(And yes, i know i can get a kit for a Greddy Type S or Apex twin chamber. I just don't want either of them.)

If you can't help with the above, any other suggestions for fitment or adapters would be welcome. Thanks.