Tank placement

[fishbuster]

Redoing a 20' Dusky with a Yamaha 200 HPDI (I know not a seacraft) With a bracket and fixing to install a 100 gallon fuel tank and was wondering if i can get yalls 2 cents.

Originally the boat came with a 60 gallon fuel tank but want to increase the fuel tank size to a 100 gallons.

The new fuel tank is 72" L x 30" W x 10" H.

The old fuel tank was 37" L x 33" w x 11" H next to the stringers and 16" H in the V.

Some people was mentioning just to mount it in the original location just have the tank go forward from there. The original location was 48" from the transom.

I know putting the boat in the water and start putting weight in the boat would be the best option but i would have to mount the bracket but still have to paint the boat. But if thats what it takes thats what i would do.

But prior to tearing the boat up the boat sat stern heavy but also had a lot of wet foam, stringers, and transom. And a heavy dusky drive.

I replaced the transom with coosa and replacing the stringers with sandwiched 3/4" plywood. also have a hermco bracket that supposedly has 800 lbs floatation (i know doesnt matter when on plane). The HPDI weighs a tad under 500 lbs.

Also planning on putting a fish box up front of the boat and that would account for 200-400 lbs. Was thinking about measuring center line of the boat and moving the tanks center alittle under 2 foot beyond that. What would yall do if it were your boat?

Thanks
Randy