I've looked through a large majority of the axle gear swap threads posted and seems like they are all 3.73 trucks to start with. Has anyone with the 4.30 swapped to 4.56/4.88?

So far all we've been pulling is a 16 foot trailer with atv's and some camping gear in the bed that is 4000 lbs tops but probably more like 3000-3250. On some of the surrounding hills, I'm getting down to 3rd gear 50-55mph 4000-4500 rpms range before we can finally maintain speed up the hill. We're now looking at picking up a truck bed camper, an older one like 80's or early 90's. I haven't found weight specs yet but I've estimated that they are roughly 1500-2000 lbs. If that is way off, let me know please.

I called one shop and asked for a quote to swap to 4.88 and he thought i'd lost my mind and told me that I'd be driving at 50mph at redline but the charts i'm seeing online say i'd only be 3000 at 65mph in 4th gear instead of 2800. Is a 4.56/4.88 swap a large enough change from 4.30's to be worth the roughly $2000 cost? I'm not too concerned with the 50 mph on the freeway and driving in the semi lane up the hill, I'd just like to be able to make it up the hill in 4th gear avoiding the 3rd gear high rpms downshift. Am I just wishful thinking?

 

What's wrong with pullin 3rd gear up hills? That's what these motors were built for

 

I cant answer all your questions but I'll say you're looking at about 2.5k for a camper or at least that was what mine weighed with no slide 9.5 ft , 3.5k+ for the huge arctic fox type.

I'll also say that if you're 4500 and 55 with your 4.30s you're actually probably in 2nd. I just did the 3.73 to 4.30 swap and was keeping an eye on speeds and rpm.

I know the feeling of wanting to keep it out of the lower gears but the reality is with any weight (6k plus) and grade of 6-7% or more, i believe you'll end up in 2nd before its over, can it be better? i don't know..

I read a couple posts from a guy with 4.88s in a green excursion, who seemed happy, perhaps he'll see this and chime in.

 

I'm the Green Excursion 4.88 guy.
I had 3.73's and we pull a 9k+(11,200GVW) ToyHauler and were dropping out of OD on the slightest of grades. I was also wanting to move up to 35" tires, so after fiddling with the tire size / gear ratio charts I decided to go to 4.88 to give me an effective ratio of 4.39 with the 35"s. 4.30 seems to be though of as the sweet towing gear for these V-10s. I have the gears but don't have the tires yet, I'm running some 32" 18"s till they wear down enough to justify the new 35's. We just pulled the trailer 1500 miles on a vacation the week before Easter, I-95 from Philly down to Savannah and back. The EX did not drop out of OD a single time the whole trip, and cruising at 65MPH in OD it was turning 2500RPM. I have pulled the same route a few times before and averaged 7.25MPG, this trip with the 4.88 and a new set of Banks headers I pulled it at 8.9MPG. Now I'm looking forward to the taller tires to see what impact they will have on the performance and fuel mileage.
If your rig sees daily duty and you run the stock tire size you may want to stay away from too deep of a gear, they do improve the tow situation but running solo I have dropped at least 1MPG, maybe a little more, most of my EX's miles are towing. Pulling your hills in third and spinning the engine at higher revs may not sound pleasant but these V-10s don't seem to mind revving, they do drink a bit more gas while singing though. I would find the camper, fill it up for a trip and hitch up the ATVs and see how much more its working, then base my decision on that. It sounds like you will still be within your truck's weight carrying and tow specs so you won't be hurting it. Then it's up to you to decide if the cost is worth the comfort and decrease in solo MPGs.
Good luck!

 

In your signature you have a 2000 model but it says 5 speed so I'm thinking it's a manual trans. If it's a automatic then you have a 4 speed. Anyway I have a '08 crew cab long bed and auto trans that weighs in at 10,400lbs with all my carpentry tools. I also have the 4:30 gears and find them perfect for solo driving. I also tow a 8200lb travel trailer up and down the hills of PA and find the 4:30's good for what I am doing. I also have the 20" wheels with a 34.2 inch tall tire, if I were to go with a true 35" tire I would go to 4:56. Now having said all of that the 3V V10's have quite a bit more horsepower and torque compared to the 2V versions and there is that extra gear in the auto transmission. Going to 4:88's would just depend on how much solo driving you are doing. If this is a dedicated tow rig, then go right to 4:88.