Hey David :
I am looking forward to here how it runs for you .
I haven’t raced in a long time but 20+years ago we ran a Sport 40 class that called for any of the 36" Dumas hydro's : - U1,U76 and Your hull with stock K&B 40 front rotor (water cooled airplane motor )
Property set up they ran very realistically ( light on the sponsons ) like a full size hydro All the hulls were close in speed so you had to nail the start to do well , often we had 7 boat starts where you could throw a blanket over all the boats as they crossed the line….
We heard comments that they weren’t fast enough ect but I noticed that most people stopped what they were doing to watch when they ran
I don’t remember anyone running your hull but I don’t think you have wasted your time on this project
I don’t remember anyone having problems with balance as long as they installed the equipment as shown on the plan so I question the need to add all that lead ( hope you made it removable )
Set the boat bottom level on a flat surface with the strut parallel and adjust from there
Throw that puppy in the water and make some rooster tails : )
Mike