My dad and I both have dodges. He’s got the 318, I’ve got the 360. They are both 1999’s. They get the same gas mileage towing or not and aside from a small 360 tourqe difference (noticed off the line with large loads) they seem about the same.
We both have 17 footers and I wouldn’t call either a large load. Personally, I’de look for the best deal. If they were identical I’d pick the 360 but I wouldn’t shy from the 318.
I’ve only had a front drive shaft go (they are unlubricated cvx joints) but I run synthentic in the drivetrain as I’m a little gunshy from stories I’ve heard. Nice thing is until now they have only been stories for both my dad and I.
Hope that helps,
jj