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Side Pipe Flange Bolt Size

When I bought my Boss it was missing the side pipes so I am assembling one from a pair of eBay side pipes and an MRT 3" clamp on h pipe. Since the MRT doesn't come with the side pipe flange bolts ( you are supposed to re-use your existing), anyone know offhand what size they are and about how long?

Grant 302

basic and well known psychic
I think it looks like an M8 1.25 ... but I'm not certain. Stock ones are press-in studs, so I don't think the hardware would be reused.

25 or 30mm bolt length should be enough, assuming you don't have the spacer block or use QTP cutouts.
ArizonaBOSS said:
All I know is they use 15mm sockets/wrench to remove.

I laughed when I read your post.....I'm in the same boat. Sometimes I wonder how do people know this stuff. But this is what make BMO soooo great!!


Tramps like us, Baby we were born to run...
Exp. Type
Exp. Level
3-5 Years
Brighton, Colorado
Funny but I just ordered a set from Levittown with the rubber grommet for my Kooks side pipe replacements. Could have used the old ones but I have a hard tyme using older hardware.

Hex Washer Bolt For Side Exhaust x4 W714780S439
Bolt Grommet For Sidepipes x4 5C3Z17C431AA
No, I have the side pipe sill mount hardware. I'm looking for the h pipe to side pipe bolts. Guess I can wait to get the parts and measure it.

Kinda cheap for MRT not to include them.


Life is short. Live well!
Bolt Grommet For Sidepipes x4 5C3Z17C431AA

Good call on the rubber grommets. When I installed my Kooks it was a bear to remove them from the original pipes without tearing them up.

Grant 302

basic and well known psychic
Yeah, that's pretty cheap not to come with the mid pipe.

Since both flanges are aftermarket, it shouldn't matter what size you run, since the original hardware has a lot of slop for adjustment/rotation. So there's no need to match it. I'd get the largest bolt that fits the flanges.


Because racecar.
Arizona, USA
superhero said:
Sometimes I wonder how do people know this stuff. But this is what make BMO soooo great!!

Because we've been there :)

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