Crumm,
Very nice work here. The way I mistreat my old Lance, I tried to spread the stress over the entire lower shear side of the camper box with 2" alum angle (screwed on with S.S. screws in the same way you did). On extreme side hilling the drivers front guide formerly left a depression in the wooden camper frame. Not good. With one cycle on and off and on, I see no change in appearance of the aluminum L's. Of course, I use the lower guides on the front too, so a long strip does double duty just keeping the box loosely in the slot. When I installed the guides many years ago, I made the clearance on each side about 3/4", With 1/8" alum. angle it is now tighter yet. Yes, it takes a few times of getting in and out of the truck even with Jeanie as a spotter as there is so little clearance. I'm still wanting to keep a little 'wiggle room' between the guides for eventual twisting of the pickup bed.
I have found my Lance does creep around in it's 'slot', sometimes the front moves right, and the rear moves left or visa versa depending on the trail. After mounting the camper, I leave the tie downs very loose until I drive forward to about 10 mph, and hammer the brakes. The cabover part bows down a bit (with the rear lifting) and the whole box moves as far forward as it can to set the two rubber bumpers tight against the front of the bed. For the first few hours of use on the highway, I will occasionally check the status of the now firm but not tight tie downs until they finally reach an equalibrium. It is surprising how much, if subtile movement there is even with a very sticky, thin bed mat. You can judge this by how the tie downs feel.
Again, nice job on something we can all use, and really need.
jefe