Dear sir I am interested in buying a 60' motor yacht built of steel. This yacht was built in 1970 by a crew boat builder using a crew boat hull. The boat has a pair of 12-71 natural's I am nthinking the boat will use about 30 gal per haour and go 15 kts.I write to ask what type of engine one might do a repower with and what the H.P. fuel consumption would be of the suggested replacement. I believe a 12 71 is worth roughly 400 H.P with scads of torque. This yacht also has 3 blade props, I am thinkng of going with high tech 4-5 blade props, also interested in your thoughts. thanks