I owned one in a dually. Worked like it was supposed to. I would buy another.
Should work good for you.
I spoke to TransferFlow and Titan when I had my 6.4 gasser, and it appears to be some DOT regs that prohibit plumbing it into the truck, but I would not see how they can prohibit the use of a transfer tank .Was it a gas dually? I'm researching aux fuel tanks and was told by transferflow no one makes an aux tank/replacement tank for a gas dodge 3500 cclb 4x drw. Have a hard time believing that in 2019 I'm relegated to jerry cans or rotopax.
...By the way, I did have the Titan 55 OEM replacement install in my dually, and I am loving the extra range.
Yes, my last truck was a gasser, and the range was terrible when pulling heavy, and I was told the same. But there are cross-bed transfer tanks that can hold gas, at least there were. My current truck is a Cummins, and has the Titan.Gas truck? I emailed titan too and they said they do not have a replacement tank for gas dually rams, only diesel. The only option they offered was a bed mount xfer tank over the wheel tub which won't work as I'm going to run a slide in camper.