GS425 Exhaust

[Spikus]

I have a 79 GS425, and need a new exhaust. There are sets on sale here, but they are for a 450. My question is if a set for a 450 will fit a 425? I believe it will because I thought the 450 is just a bored out 425, which is just a bored out 400. I believe the engine and frame are the same for all of them. I've found new sets for sale on ebay, and they say they fit GS400 - 450, which would back up what I'm saying. Does anyone know for sure?

Thanks,
Scott

[BassCliff]

Hi,

The exhaust gaskets are the same part number. This leads me to believe that the headers will fit. But as you can see from the parts fiche pictures below, the rear mounting is a little different. This may not be an issue, especially if you have modest fabrication skills.

1979 GS425E:



1980 GS450E:



I'm sorry I can't be of more help.


Thank you for your indulgence,

BassCliff

[Spikus]

Thanks Cliff!

My fabrication skills are almost non existent, so the differences between them at first had me worried. I went back and looked at his pics of the exhaust though, and it looks like the NOS set he's selling match your diagram for the 425 exhaust, so I'm very happy! Nice coincidence.

[pete]

Look up the fitting guide for the Mac 2 into 1 that is commonly available. Pretty sure you'll find it's the same for the 400's through 450 so I think you're probably good to go...

[Spikus]

I saw that 2 into 1. What is the advantage to that over the stock setup? More back pressure?

[pete]

Mixed reports on whether they're good or not, but I was just meaning to check the fitment guide to confirm if they should be the same for all the 4xx twin models...