I am not sure of the whole head being interchangeable since I am not sure on the FI mounting vs. the carb mounting. Also have the bearing journals stayed the same in the later bikes? (probably since early EFI did) Don't know the answers but those are some of what comes to mind to look for. In your case I would imagine as long as the journals are the same and it is from a 270ยบ engine you should be OK for selling purposes.

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