Thanks for all the responses guys. This a really active site, and I can see myself coming here a lot for opinions of people that have been doing this a lot longer than I have. I'll mention couple points to clear up confusion from some of the replies.
- The camper is relatively light weight compared to most, so I'm not really concerned w/ the increased CG associated with the larger wheels and tires. The bed height will only be increasing about 2" above stock (from the frame rail) Hopefully experience will prove me correct.
- The camper is designed to be bolted down. Being a flatbed model, there are no other places to attach to. Frame twist does bother me a bit, but the manufacturer assures that is is acceptable.
- I've heard from many people that the 4r100 is the relative week link in these trucks due to the power available from the engine. Gears will definitely mitagate that somewhat. Even if I can build more power to overcome the lower that factory gearing created by larger tires, I don't see that as the proper way to use that power. I'd rather have the gearing set up as it would have been stock, and any extra power is power that will improve towing/driving that much more.
- With the 35" tires, new 4.10 gearing will be the same as stock 3.73 gearing. 4.30 gearing will be similar to stock 4.10 gearing. Even with 4.30 gears and 35s, the RPM at 70MPH will only be ~2,085. Still very acceptable for the 7.3 in stock form.
Here is an example of the camper on a newer Dodge with a similar flat bed:

Don
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