Chain Run

Fitted a new 38T rear sprocket and fitted an old chain to calculate the length of new chain needed, but ran into a few issues previously overlooked or missed. 

I really need an 8mm offset front sprocket which will line up with the rear chain on a standard un-shaved carrier and also clear the inner face of the chain tunnel of the swingarm. I was hoping a 4mm offset would work but the chain is too close to the swingarm.

Running the 8mm offset or any offset for that matter creates 2 problems, (a.) the chain will hit or run too close to the exhaust and (b.) the chain and sprocket will be too close or hit the clutch pushrod actuator on the inside of the side case.

Problem (a.) can be over come with a secondary chain roller ?????

Problem (b.) ?????