Fuel Tank - Plastic?

[Snookerd]

my 23 Inboard was converted to a bracket with twins and the original space under the console for the Diesel is where the prior owner put 2, 50 gal tempo tanks and it works well.

[1bayouboy]

My '74 tsunami was originally an I/O.....apparently it go a
110 gal aluminum tank in 1989. I'd like to go a little
bigger during my refurb....maybe 130 or 140. Post I've read elsewhere say that over 50 gals or so to go aluminum....curious about everyone opinion on this board. Also looking for sources....I can search the net but hearing from people that purchased tanks helps.