I have a 75 Challenger that still has the fiberglass tanks. I really need to get them out as they have already started sweating resin into the carb. Destroyed a fuel pump, uncountable amount of filters and I've had to take the carb apart twice. Need to get em' out of the boat.
It looks like my fiberglass ones are about 8" in width.
I would also consider doing the round tanks with straps (preferred) but give me a holler and let me know what you have. Trying to make it to the river for memorial day weekend. 801-792-2192 Johnny.