As far as I know 15+ full system should fit on 17. Easy to confirm if you go to woodcraft site, compare full systems between 15 and 17.
No more 17 exhaust threads or I'm going to murder a kittie
He's talking stock systems. Yea mate it will fit you're only issue will be your rearsets don't have the hole in them to hold the exhaust so you will have to get a set of stock rearsets off a 15/16 or just get an aftermarket set like attack.