If they are that single-18 "subscoop" type cabinet (SH1810L, T18, or whatever other model numbers it was sold under) Then EV themselves sold front-loaded earlier versions before flipping the driver for later versions of the same box -they did change to a higher power driver, perhaps it was their way to accommodate that without re-tooling the box?
Anyways having the motor structure outside the box has got to benefit cooling and onset of power compression even if by just a little bit
They are a single 18, not to heavy. I have moved them a hundred times and seen the number, but i have shit for memory. The SH is the one, i think. I will read what i can find about them when i have time and see what EV says the difference is (spec sheets are always right) in them. Looking forward to messing with them when it warms up outside.