Merc 377 Upgrade to 410?
 

I currently have a 09 SeaRay Pachanga with the 377/6.2L (320HP), boat weight is 5200lbs & it struggles with passengers & full tank of fuel (50Gal) to get on step. Wanting to stick with a small block to ease in the transfer of parts, pumps, pulleys, ignition, etc... With programming/Updating the ECM, larger injectors can the factory intake be used? or would a Edelbrock or RamJet style intake work best with the larger 410 cid or even a 434 build?

Looked into the Whipple supercharger option but they don't offer it to be used with my digital throttle (DTS)

Thanks in advance for your reply!

By the time you get done building and tuning, you'd be better off to swap to a stock 496HO

What he said.