1989 41' Viking Repower

I replaced the 6-71TI (485hp appx. 6000lb w/gear) with the new electroinc Yanmars (480hp appx. 3200lb. w/gear) also replaced the steel engine beds with aluminum. The yanmars are a lot narrower and shorter I gain appx. 8 in. between the engines, appx. 4 in. below the salon floor and moved the engines 7 in. forward so that the coupler and transmissions are well forward of the bulkhead for service. The engine compartment is alot easier to move around in and the heat and noise in the salon is considerable less. The yanmars require 5 in. exhaust we had an adapater made and used the orginnal 8 in. exhaust system which makes it very quite at the transom at trolling speed or faster you do not hear any exhaust noise. The gear ratio is 2.5/1 turning a 4 blade SS prop 24X32 (was 1.5/1 turning a 24X23 3 blade). The weight lost has made the boat tender even at the dock with full fuel and water, the stern is appx. 2-3 in. above the org. water line. Before and after proformance: Detriots cruise 18kts@34gph top spd 22-23kts...Yanmars cruise 26kts@34gph top spd 29.5kts @ 42gph (23.5kts@28gph) it will go from 4.5kts to 20kts in appx. 8-10 seconds. I am going to have to add some weight to stabalize her. My cruise range with Detroits was appx. 230 nm. (425 gallon tank) I should be close to 300nm now. I fished a tuornament with 13hrs. on the engines left on Fri. nite returned on Sun. total run time 29hrs 4hrs@cruise(34gph) and 25hrs trolling(5gph 8kts) total fuel burn 275gal. Tagged two blues so I assume they like the new sound.