the exhaust will be a crossover coming off port side now and we're going to go to straight pipe and divert water to steering cooler . This will give us cooling water for hydraulics when engine is started versus relying on electric pump which we have now to cool hydraulics.We had to step up transmission sizes to accommodate for size. The zf gear originally quoted didn't fit too large at bottom back side. Going with twin disc 5095 rated for 800HP which has taper and Jay at RI Engine said should work. More expensive ,but it beats having to redesign shaft etc..soft mounts still. I really didn't want to change much of the dynamics we had previously as boat ran flawlessly ,was quiet ,efficient, and most important raised fish.. With the 620 , hoping for higher cruise speed for the long runs to the east,,