| Just a thought, but if you are thinking of fitting a set of high level exhausts you might be better off trying to fit the single seat to the existing subframe.
On the 851 single seat subframe the exhaust hangars are very low down, so you have to cut them off and try to weld ( or bodge ) some brackets on to take a high level exhaust. The dual seat subframe already has brackets in place. It might be worth seeing if you can get the single seat to fit ( without resorting to cutting or drilling it of course ) before buying another subframe.
Best of luck! | 
Threaded Mode