Inter-changeable engine

[shane BBoys]

Chaps.
I'm going to build a series 3 engine ( Mugello ) which I intend t put on a series 2, someday. but in the meantime was wanted as mentioned a back up engine, I have most of the parts so far for the build including a JL which came of a mates GP, so when I eventually get round to fitting the engine into my series 2 what can I do about the exhaust IE panel clearance, is it a different end piece before the can or something else that can be done.

Cheers Shane.