What engine would you build for a Ramcharger?

best mileage is going to be with a FI 360 Magnum
then the 318
then the 360
It takes the same amount of power to drive the truck down the road but for several reasons the 360 does not do as well as the 318
maybe if the 360 had the 318 heads or late 360 heads and pistons to give some quench, good compression and cam to match it could do better than a lower compression 318- have to think about that one but Aj has given the comparisons
318 can be better with the right compression- pistons are the problem
I had a ls one in a 28 ft motorhome- amazing motor so much better than the 454 with in a Winnebago