bitsamonkey, Many years ago I replaced the Galvanized tank in my 20'SF with a poly from west marine. best fit was one where 2 of 3 diminsions worked only not as long so it doesnt go all the way under the seat. Mine is a deck mount in the console though. Think I had to sacrifice about 5 gals but I rarely run too far.
Chances are yours is a in hull tank so this info may not help. You can just see the tank under the console below
Thanks all for the info on poly vs alum.
