1980 Overnighter gas tank install questions

[Mastrouble]

Hello all,
Getting ready to install the plastic gas tank the p.o. included. I've researched a bit and crossed off several questions on my list. These ar what I have left.
1) being a plastic tank, I presume I dont need neoprene pads. If not, should I block it up with pressure treated 2×4 or foam to make it level with the floor?
2)I plan on using 2x pressure treated across the top of the tank and under the cover as bracing. Should I wedge some along the sides to secure the tank laterally? Better ideas?
3) what would you use to deal the cover to the floor?
Thanks in advance.

 

[Uncle Joe]

I am no pro but I can tell you some of the things I learned changing out the main tank on 2 different Offshores.

Do not foam in a molded tank....they need to expand and contract. You also must have clear space under the tank for water to drain aft. Not just the tube that connects the front bilge to the aft.

Mine had mahogany or teak wedges, 6 or 8 maybe.....they were what held the tank in place...front to back and left/right.

The tank has to sit below floor/deck level to allow for 2 or 3 pressure treated 2x4's....on the flat across the top of the tank...secured to the stringers.....they not only secure the tank but support the deck plate.

I am sure others here can add better info but this worked for me.