I am looking for the rubber accordion boot to seal between the cab and box. I have found some that are up to a 4 1/2" gap but I have a round a 5 - 5 1/2" gap on my conversion. It does have a lip on the truck and the box it just pushes down on. Any help appreciated. Thanks, Larry.

https://uni-grip.com/Products_Page.html theses guys have all the sizes you need and they are very reasonable. I used a 7 inch on my FL60 because it stretches from 2 to 6 inches. works great.
Doc Weaver

Thank You for your help.

On our coach we have fabricated a z-channel to attach to the cab and another to attach to the box. Welded solid at the seams to make 2 picture frames opposing one another and then an accordian seal between both. Works great with an air ride cab or fixed cab.

Thanks for your help. Picked one up from uni-grip. Great company.