[scottz]

I wouldn't lose any sleep over it; either rear end will be fine. I have the same trailer as you and I have a 4:10 rear axle. It pulls great, but so did my previous Ford with 3:73's. Running 65-70 in 10th gear, I think it turns about 1800. I get 11mpg towing and 13-14 empty; I assume the 3:55 might do a little better.