mine is an 87 (w/454 engine) and i honestly doubt the installer reinforced the fiberglass. since i didn't see what it looked like under the gunnels, i can't say for sure, but i probably would have reinforced them if i did it myself. but, like most diy'ers, i tend to over-do things. i can tell from having taken a quick peak that there are wooden backing plates to absorb stress.

i haven't noticed any flex at the deck and there are no spiderweb cracks anywhere near the tower legs. its really sturdy even with speakers and board racks full.

even if you have to slap some fiberglass in there, it doesn't have to look good. i'm so glad i got a tower, it's a whole new boat that's even roomier now.