2 years ago had a ss180 top end converted to a P200 (piston, tuned cylinder and head) by MBD. Bought new crank from SIP, but on checking found it to be GS160 crank (45150000). Can I use the 160 crank with this set up ?
Looking to also uprate clutch and electrics … advise please.
Could I also use short 4th gear on this set up ?
Looking to utilise ss180 top end on GS160 engine. Is it straightforward as manuals seem to imply ?

The GS conrod eye is 15mm and the SS is 16mm meaning you either need to use the heavier SS crank or split the GS one to fit an SS 'rod.

Alternatively,if you want to use a modern ignition,then buy a full circle crank(P2 I think but measure up for the webs first)for a PX and use the stator plate and flywheel for one of those.This should also allow you to fit a P2 or Cosa clutch(again you will need to check the clearances.

I doubt you’ll need a short 4th but here’s a gearing calculator for you.

Why not join over here and ask Guy,he’s far more knowledgeable than me.