Juat a heads up for anyone looking to do this mod on an AR240, the Pacific Aerials mount appears to be just a little too big to fit on the AR240 towers. Even if you trimmed the corner like
@Mainah the long edges would hang over the flat of the crossbar and the screws may not go into a flat surface. Apparently the crossbars are not only hollow, but a little smaller on the AR boats compared with the Limiteds. With that said Shakespeare makes a similar quick connect mount, the QCM-S, that has a smaller base plate that appears it will fit with no trimming. I believe this is the mount that
@Sbrown is using in his picture above. Only downside to the Shakespeare mount is it's not as sleek looking (lever vs knob for ratchet mechanism) and the antenna options are more limited (white only and no 6' option).
I found dimensions of the mounts online and printed out to-scale templates. Pictures are taken on the upper crossbar:
Here's the Pacific Aerials P6759
View attachment 75074
Here's the Shakespeare QCM-S
View attachment 75077