With the fuel management systems now available, why would you want to have a reserve? you should know exactly how much fuel you have if its important to know.

Now if you said you wanted two tanks to change how the boat rides based on weight distribution, that's another story.

Did you price RDS in Perry?
http://www.rdsaluminum.com/

They made a perfect replacement for my Seafari when I needed one out of 1/8" aluminum, which matched the original thickness. It was about 2006, but the price was comparable to similar capacity above-deck poly. Retail invoice was right under $8 per gal.

(Although I have to admit it actually cost me nothing as they built it as a "display" for ProLine, who then "comp'd" it to me. It helped to have a parishioner who was a VP).

Fish old motor and your right about the balance

send fossilman a pm he is on this forum and makes real good tanks at a fair price.

When re gas tanking, always remember the 1/3 rule: 1/3 to get you there and loiter, one third to get you home, and 1/3 for weather/ emergencies/ mechanical reserve (increased fuel consumption) conditions. The older I get, the more have been reminded that it's a great rule of thumb.
Before the day of fuel management and flows scan, we'd set fuel gauges so that at rest, at 1/2 fuel level, the gauge was dead accurate, or a bit pessimistic- best to know where you were at right at the point off no return.

Called Sunshine Marine today. Quoted me 1350.00. I'm going with them. They were half of a competitor. Great people to deal with. I highly recommend them. Also if you are wondering why I need 165 gallons is because I have 2-150 ocean runners. I'm taking the boat offshore this spring so I needed a new tank. ( original added on to..crappy job.. Foamed in) the motors run perfect so I will wait till these blow up before I buy a fourstroke. Now I have a little money for a Garmin. And the list goes on and on and............