Ckid

I have a 1999 f150 5.4l auto with 3.55. Gone from 255 70 16 to 265 70 16 tires want to tow 6820 lb dry weight camper should i go with 4.10 or 4.30 rears. Thanks

mass-hole

that doesnt sound like much of a size increase. Thats what, a 31" tire? I wouldnt go to big on the gears otherwise you may end up just spinning to the moon. 4.30's and 31's is gunna suck.

bubbabud

Not all that much difference between 4.1 and 4.3 and as far as towing with 31" tire the 3.55 will pull any thing that is within the payload and towing capacity of the truck.
Remember no changes you make can change the weight rating assigned by the factory at build.

chimmike

7000lb dry weight doesn't mean much.

you need to figure out your truck payload first, determine if it's rated for that and all your passengers and gear

Ckid

It said 8000 towing. In oners manual

bubbabud

Just pulling the trailer is such a small part towing. you need to know the loaded weight, the tongue weight, the weight of passengers and gear, the gross vehicle wt rating, the gross axle wt rating and with that much weight you will need a WDH and working trailer brakes.
You should also study the laws and regs for the area you plan to tow.
Yes you can just hook up and go and may even make the trip but god forbid some thing happens the plaintiffs attorney will have a field day in court.

PerryB

I'd go with the 4.10's. I put 4.56's in the '05 with 35" tires and it's great, but I wouldn't want to run anything shorter. Even with 33's I'd recommend 4.10. Also, if you have a 9.75" rear axle (and I think all the 5.4's do) I don't believe there is a 4.30 gearset available. When I did my re-gear about 2 years ago, 4.30 was unobtanium.

Ckid

Ok the camper tag said 6820 dry 8000 gross and my f150 said 8000 gross i know im pushing it to the limit. I do have wb hitch. I want to gear so im not in a strain on hills. The camper is a key stone 29 foot.

chimmike

you're only reading bits and pieces of what we're posting. Go back and read it again.

I asked what the payload rating is for your truck? How much gear in the the truck/bed, and darn near 8000lbs loaded in the camper?

Eric Kleven

If you have the 3.55:1 right now, you won't be struggling that hard. The engine will either be running 2,400-2,700 in direct, or 3,500-4,000 in 2nd. Neither of those are real hard on things. Depends on how much towing you plan to do. Like the other guys are saying, make sure your tongue weight + other crap in the truck isn't going to put it over payload capacity.

If you're dying to drop the money on more gear, go with the 4.10's. Depending on the manual, it might bump up your tow capacity a little bit, but don't take that to the bank. Personally, I'd put the money into some air springs in the back, maybe a good tune, and save the rest for fuel.