The reason there are different versions is because they have different fittings.
The earlier 8v Twinsparks had a flange fittings,
Whereas the later 16v tended to have a sleeve fitting.
the earlier system can be made to fit, you would need to replace the flange fitting with a flared pipe to go over the outlet from the cat.
It also depends what you want on the exhaust.
The standard has 3 boxes after the cat, one right after, then a triangular one in the corner by the back wheel, then the backbox.
You can buy 'off-the-shelf' Stainless systems - I have a Ragazzon single box set-up.
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