3.55 gears vs 4.10s with gear vendors

[Ruffnek7tree]

Hello all, something I have been mulling over the last few days, my truck is still a n/A idi, plans to swap a turbo on eventually, has 4.10s now, and it's kinda miserable at highway speeds lol.. as the title suggests, debating on 3.55 gears or keeping the 4.10s and installing a gear vendors..

I also have a kp 60 to swap in, it has 4.10s in it currently, but it might need a rebuild, haven't torn into it yet.. the ttb is getting close to needing a rebuild, so might as well swap the 60 in.. I also plan to setup my truck for towing my gooseneck, which weighs around 5k by itself, hauling vehicles and what not when I need it..

I see the pros for the gear vendors na and turbo as having more gear choices when towing, and better rpms at highway speeds, under drive would be good for the gaps in between gears on the zf5, etc..

Cons would be more complexity, potentially more expensive, although I plan on buying everything used as much as possible lol

What is everyone's thoughts on this?

 

[Nero]

I would suggest doing a turbo first. Stock turbo with no head studs, my cclb with 4:10 did 65 just fine in the hills of the PNW with a camper and boat in tow. Also stock ratio zf5.
Better bang for your buck in my opinion.

 

[Ruffnek7tree]

Thank you for the reply! I currently have the turbo setup, just having the time to install it more or less while not taking the truck off the road for too long..

What I meant by miserable on the highway is the 24-2500 rpms at 68-70 lol it does ok enough as it is, just being able to comfortably cruise in the 70-80 mph range would be really nice.. I know that the turbo will help immensely with drivablity, and will likely be the first thing I swap on.. but I'm trying to plan long term lol.. which would be better in the long run type

 

[Nero]

With my turbo, I'm now head studded and intercooled with a 3" down pipe and 4" exhaust no muffler. I could push 75 but my egts get a little hot, and then my coolant temps start to saturate. If you do different gears, just remember you're changing the load range on the engine, working it harder, there are other things you'll have to do to accommodate it.
I found my truck runs the absolute best at about 66-68mph, even with the rpms pushing 2200-2300.

 

[u2slow]

I wasn't too keen on the 4.10's in my '95 F350 crew... but between some heavy payloads and finally bigger tires, I'm glad I left the gear ratio alone. Was a 5spd truck and l no GV.

Edit: my buddy's 90 IDI had the 3.54, and it was a better match for daily driving and running empty.

Edit2: the bigger tire thing... i need/want at least 33" tires to get the load capacity I want.

 

[FrozenMerc]

If you put a Gear Vendor behind the 5 spd, giving yourself a double overdrive, stay with the 4.10's. A double OD and 3.55's will make the top gear all but unusable, especially with an NA motor.

My truck has a 3.73:1 rear gear, ZF 5spd, Turbo, CDD 90 cc pump and an Oregon cam. The 3.73's are the perfect compromise between towing power and unloaded cruising.

 

[Ruffnek7tree]

Thank you for the feedback! That's kinda why I have been debating on doing the gear vendors, sorta best of both worlds, 4.10s when I need them for towing and lower rpms when I'm just daily driving empty..

I don't want to go over 285s on my truck, even when I rsk the front, I have enough headaches with a lifted truck in my 01 powerstroke lol.. I just want a standard tire size, maybe I'm just getting old

 

[MtnHaul]

I have an N/A 7.3 with 4.10s and love it but yeah 75 is about it on the highway. My turbo 7.3 with 3.55 is much nicer on the highway. I would add turbo and swap to 3.55 before a GV. Of course if you're towing heavy in the hills you might want those 4.10s and just learn to like 70-75. Besides, unless you can maintain a higher rate of speed for a lot of miles you don't really get there much quicker and you pay for it in less fuel efficiency.

 

[IDIBRONCO]

Personally, I would want the 4.10s and GV OD. Like you said, you'd have lower gears for towing and the OD for running empty.

 

[Nero]

I guess the big question is what are you using your truck for? Loaded a lot of times? Unloaded? Doing lots of hills?

 

[Ruffnek7tree]

Main would be running around unloaded, but when I am going to be loaded, probably heavy, as my gooseneck by itself weighs about 5k, get a 5k truck on there, about 15-18k combined weight with the truck lol.. a lot from an idi, I know, but it will do it, just not very fast lol

Hills and mountains are in my normal stomping grounds, PNW, montana and north dakota, hence why I'm thinking about the 4.10/gv combo vs 3.55s, it will be turbo either way eventually..

 

[MtnHaul]

Yeah it sounds like 4.10 would be better if mountains are at all in your normal routine. I guess I find the cost of a new GV setup to be so off-putting that any reasonable alternative sounds better even though I often thought about how nice it would be to drop my RPMs on the highway yet still have more grunt on the hills.

 

[The_Josh_Bear]

Main would be running around unloaded, but when I am going to be loaded, probably heavy, as my gooseneck by itself weighs about 5k, get a 5k truck on there, about 15-18k combined weight with the truck lol.. a lot from an idi, I know, but it will do it, just not very fast lol

Hills and mountains are in my normal stomping grounds, PNW, montana and north dakota, hence why I'm thinking about the 4.10/gv combo vs 3.55s, it will be turbo either way eventually..

This pretty much seals the deal to keep her 4.10. Besides it being way easier! You can see my mods in my signature, I used to have 4.10's and now 3.55's. But I also really enjoy these bigger tires(285 75 16) and the combo isn't great for towing. Max I have towed is about 7k and it's fine, but the 2-3 shift is reallllllly long if you're starting on a hill. Overall it would be better to have the tighter gear splits and then pop into GVOD.

Now for unloaded or small loads/campers I have a pretty sweet rig. She does anything I want her to do and does it pretty quickly. 75mph is very comfortable, though not great mileage. As for power and drivability I've bottomed out the speedo a few times just for fun. 85 is easy though I wouldn't live there unless it was the speed limit. I highly recommend a tight steering setup and to adjust/replace the steering box if your front end wanders. Seems like these Fords are so easy for owners to neglect in the steering...it's not that hard, people!

 

[Nero]

Seems like these Fords are so easy for owners to neglect in the steering...it's not that hard, people!

Uhh yeah it is!

 

[silexis]

I've got 4.10's a turbo. 5spd and gear vendors. I use the GV a lot. I think cruising at 65mph is around 1800 rpm.
The gear splitting is not that useful, as a lot of the gears are the same: ie 3 OD is the about same as 4th.
The only 'problem' I have with the GV unit is that you have to change the lubricant fairly often, at least every 10K miles. The GV 'filter' is just a stainless fine mesh screen. The fluid gets dirty fairly quickly and sometimes needs changing more often (5K miles or so). The unit does not shift with dirty oil. With a deep sump, the unit holds 48oz. Oil changes are easy.
I've got about 200k miles on the unit. About 75K miles ago, it quit shifting even with fresh fluid, so I opened it up and cleaned it out. After the cleaning it shifted fine.
Overall, it has been very reliable. It would be nice if it had an external paper filter and longer oil change intervals.