First off, welcome to the forum! And nice seeing your first post was in the Laveycraft section
2750 Merc 525 will push this boat to the low to mid 80's. It weighs aprox. 4500lbs.
29 Merc 525 this boat would run mid to high 70's and weighs aprox. 5500lbs
Both boats share the same bottom design and LOVE the rough water. They will not be the fastest boats in calmer waters and will actually handle better in choppy water.
The weight of both boats that I posted are aprox. because Lavey offers different options in lamination which will affect the weight. Also, pending options boat has...
Now you say you are building a 565ci 680-700hp motor for the project...
Pending on setup (weight,drive,box,X) that HP will push an average 2750 in the low to mid 90's. The 29 will run mid to high 80's