4.10s, 3.73s, or 3.55s?

thatsmokinobs · Oct 14, 2015

Ok I have the opportunity to trade my 4.10 front and rear axles for the 3.55s out of my buddies dad's truck and I'm wondering is this worth it? I don't do much towing at all with my truck, but I do take it back and forth 4 ish hours to school and home every couple weekends. What will be the downfalls of the 3.55s if I trade him? I know I'll get less torque, but like I said I barely tow anything, but I do also live in PA which is all hills. Or should I just wait for some 3.73s?

thatsmokinobs · Oct 14, 2015

Another thing is I'm gonna get 35s when these tires get too low, probably this summer or earlier, and eventually 38s but that's not until a long way down the road. I know that 3.55s aren't gonna be enough for 38s, but what about 35s?

zilla68 · Oct 14, 2015

I have 3.55 and 35's and if I were you id keep what you got

thatsmokinobs · Oct 14, 2015

Yeah the more I think about it, the more I feel I should stay with the 4.10s.

Bugman · Oct 14, 2015

Also unless you are experienced in swapping out gears or are having someone do it for you this job isn't for the weekend mechanic. That is unless you are swapping out the whole axle.

Powerstroke Man 6.4 · Oct 14, 2015

Keep the 4.10's.

thatsmokinobs · Oct 14, 2015

We were just gonna swap out the whole axle. Already tore my front axle down to just the empty pumpkin and tubes. That wasn't fun and I'm not gonna do it again, twice lol. If I do it, I'm gonna repaint the new axles and steering parts the same white as the rest of the truck and repaint the leaf springs black while I can get to them easily. Plus fix any problems/change the gear oil. But yeah I doubt I'll do it

Foxcobra1 · Oct 14, 2015

Keep the 410s, it will be a dog with 35s and 355s.

JCart · Oct 18, 2015

Really depends on what you're using (planning to use) the truck for. Towing lots or 38" tires I'd say stick with what you got.

My CCSB is 3:55 with the ZF and love it, mind you it's not stock and with stock turbo and E4od I hated it (35" tire), was a laggy piece of keerap. 1.0 housing, tunes, 'jectors, IC etc etc way way nicer to drive. It's basically a work princess that doesn't really tow that often. So mileage wise it's nice with.

ECSB is currently E4od with 4:10s and is my old man full stocker truck, it ok for towing the 5r but for work (red truck has been down for a while) I hate it on the highway.... Way too high rpms...
jrc

Diesel_Brad · Oct 19, 2015

NOT worth going thru all the effort.

While I have had both and the 4.10s with 35s Pulled awesome I am really liking my "new" truck with 3.55s and 35s. I cant wait till I get all the power adders to it to make up for the power loss with the 3.55s

JCart · Oct 20, 2015

Diesel_Brad said:
NOT worth going thru all the effort.

While I have had both and the 4.10s with 35s Pulled awesome I am really liking my "new" truck with 3.55s and 35s. I cant wait till I get all the power adders to it to make up for the power loss with the 3.55s

For me this is the ideal set up (or at least what I'm trying to refine). Good mileage for a DD, (18-20 mpg hi way imperial gallons) can pull heavy in a pinch and has goodly amount of power, like in the 400-450 RWHP range and reliable. No lag, power off idle and don't really care about power over 3000 rpm. Over 3000 rpm with 3:55 and 35's is way too fast where I live.

what power adders you considering Brad?

jrc

Diesel_Brad · Oct 20, 2015

JCart said:
.....

what power adders you considering Brad?

jrc

Injectors, turbo, I/C, E-fuel, etc

wadeclinton · Nov 22, 2015

I had 3.55, 35's, and E4OF in my eclb when it was TTB. With it mostly stock and a crummy tune (edge). I hated how it towed. On the flats CA HWY 99 or I5 it was ok. But going over CA 58 or I80 I had to run between 2nd and 3rd. This was with a 24' travel trailer or my 18' deck over.
I swapped to 4:10 with a Dana 60 conversion. It was better. I could hold 3rd gear on those hills if no one did something stupid in front of me.
I've recently done a ZF6 conversion and have found it better now as well.
IMO for 35" tires and hills the 4:10 gears are the way to go.

old man dave · Nov 24, 2015

Heck, I like the 4.10s with 33s, especially while towing 10k.

3850 rpm rev limiter gets up to 120mph (not while towing) with my 160 stageII setup and even a 1.0 for my speed fix.

morefuel · Nov 24, 2015

With an auto i would say keep the 4.10s but with a zf i would say go for the 3.55. With 285s i noticed no difference or very litttle.

Baker42 · Nov 24, 2015

I have 315/75/16's on my 95 with 4.10's and love it. 3.55's would probably be a dog.

powerjoke4life · Nov 24, 2015

Personally I like the 3.73's. As someone who doesn't tow all the time it helps me out a little on mileage and the truck still tows just fine

thatsmokinobs · Nov 29, 2015

If I'm getting approximately 20ish+ on the high way with 265/75s, 4.10s and that POS e4od, what kind of increase would 3.73s and a zf5 swap gain me? Just curious

Diesel_Brad · Nov 29, 2015

Ive never seen over 19mpg
97 reg cab zf5 4.10s with stock tires, 285s or 315s

Never saw over 16mpg
97 Crewcab zf5 4.10s w stock tires, 285s or 315s
97 Supercab zf5 3.55 short bed 285s or 315s
94 Reg cab zf5 4.10 33's