yea i have 3.73 gear with my 39.5 tires and it is sluggish..i keep my edge on level 5 so it gets up to speed quicker.
gears would be a first consideration to help with mpg and less stress on trans
also be prepared to pay 1600 for a new set of mud tires every 30k miles..i havnt found any tire that exceeds 30k by much so if u drive alot it keeps the bank account low
my buddy has a 10'' lift on his '03 f250 gasser and he is running the 41'' irok radial tires-which is what im going with here very soon..and he has rubbing on full turns b/c the inside of the tire hits the front leaf spring. the best idea if ur made of money is to go with hte semi style rim and some michelin 200k tires..its a $5k upgrade though.im lookin at doin that after i wear out my next set of 30k mile mudders
besides that,the only thing i came into a prob with is a drop hitch for my reciever..i got a 10'' drop and its still too high. really need a 12'' drop for most trailers.
good luck with ur decision..ill be around if u have any more q's