I have 4.56 in my axles with the titan box/205 (exact same gearing as your magnum/205). And though my blazer is a much different animal than your cclb, and I still have a 350/700r4 in mine, still I bet you would probably be happier with 4.56's in your truck, just thinking about how you use it. It would make it much more tolerant on the highway, and even towing your camper the low-end torque of the BBC should still allow you to tow your camper just fine, and off-road it shouldn't make that much of a difference because of all the gearing options you have in the magnum setup. When I put mine in double low and 1st on the tranny (sure 700r4 has lower 1st than 4l80e, but I'm on 42" tires, a bit bigger than you too, so it kinda evens out) and anything other than slow technical rock crawling, it's almost too low, haha. So I bet you would be much happier with that for sure