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4.10's and 35's with overdrive

G-Force8

G-Force8

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If I use the axles I have that are said to have 4.10's in them with a set of 35" tires (likely BFG KM2's) will the overdrive in the 700R4 work properly?
 
it should people run that combo alot, but i have 4.56s and 35s with a 700r4 and i wish i would have gone to 4.88s, 60mph and 2000 rpms give or take. wish i would have went a little deeper
 
It lugs a little and any incline (Head wind) will cause it to downshift. Be carefull if it starts hunting (Shifting up and down) this will cause excessive heat and burn up your tranny.
 
I ran that combo for a very short time. The 700R4 doesn't like that combo too much, hell it doesn't even really like my 4.56's and 35's. I wish i would have went with 5.13's instead.
 
I ran 35's with 4.10's & an SM465 (no OD), and I thought the combo was just about right. you better have a cam with some serious low end grunt of your going to hate it IMO...

different vehicle w/ 700r4 & 33's it ran at to low RPM, and my mileage sucked I hated the combo.
 
I have the same combo (except manual tranny) and I can't use overdrive much unless I'm traveling 75+. A big block motor would probably be good for that combo or try deeper gears.
 
Don't have the money to re-gear right now. Basically my options at this point are the 4.10 geared K20 axles that I have, or I have access to a rear end that has 4.56's in it,but then I'll have to re-gear the front axle before I can wheel it.

I don't want any issues with the 700R4 "hunting" gears or downshifting sporadically (I already don't like the part-throttle downshift they have stock as it is). The tranny is a 70k-mile GMPP new replacement that had a cooler installed when the tranny was installed,but, I wouldn't be able to re-gear to a lower ratio for some time and by then I wouldn't want to be re-gearing for 35's. I want to run 38.5's-40's eventually.

the engine is a completely stock TBI350 with 220k miles on the ticker. I plan on changing that too,but I'm uncertain at this point when that will happen. Either a MPFI Vortec 355 or a Big Block swap is in the future
 
well - I think a 350 would even do ok with this combo if you had the engine built to be a stump puller. if that is what you can afford drop em in, and see how it works out. worst case scenario you can leave it in drive instead of over drive.
 
solowookie said:
well - I think a 350 would even do ok with this combo if you had the engine built to be a stump puller. if that is what you can afford drop em in, and see how it works out. worst case scenario you can leave it in drive instead of over drive.
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Well, I guess leaving it in drive would get the rpm's up enough to blow the 221k mile 350 and at least force a rebuild:D

but the money isn't really there.I'd have to max out my new $3k credit card :haha:
 
I built a stock engine with just a cam change, and nothing else. I had headers, and exhaust done. I had 35's on it, and it equated out to 15-16 MPG @ 75 MPH.
 
my burb has 4.10's from a k20 and 36" sx swampers. great for around town. od is pretty much useless unless you like destroying trannies. 65 mph on the interstate is about it. my solution was to keep a set of 16" ford van rims and tires for any towing i do, or interstate trips. until i stumble across the funds for a cummins and a 5 speed, then it'll be 3.54 gears.:D
 
id run the 4.10s for now, cus if u have to regear the front axle to match 4.56s, id wait till i had enough to regear both axles deeper. i have 4.56s and really wish i had something deeper, just dont have the take off i feel i should have.
 
When I was picking gears and stuff for my truck I found a calculator on the internet, cant remember the website now, but after looking at it I went for 4.88s.

If I were you Id just keep the 4.10s and run in drive till you get enough money for the regear.
 
bftank said:
my burb has 4.10's from a k20 and 36" sx swampers. great for around town. od is pretty much useless unless you like destroying trannies. 65 mph on the interstate is about it. my solution was to keep a set of 16" ford van rims and tires for any towing i do, or interstate trips. until i stumble across the funds for a cummins and a 5 speed, then it'll be 3.54 gears.:D
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Thats good to know. I'd like to be able to have O/D but I'll prob have to compromise and keep it in normal drive and let the rpm's rise on the freeway. I actually have some little roller tires/wheels on the axles now that I could use for towing.

chevyuser74 said:
id run the 4.10s for now, cus if u have to regear the front axle to match 4.56s, id wait till i had enough to regear both axles deeper. i have 4.56s and really wish i had something deeper, just dont have the take off i feel i should have.
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That makes the most sense. Keep the k20 axles until I have the $$ to gear down to 5.13's and swap a D60 front in place of 44 at the same time when I step up to 38ish" tires.

Drey said:
When I was picking gears and stuff for my truck I found a calculator on the internet, cant remember the website now, but after looking at it I went for 4.88s.

If I were you Id just keep the 4.10s and run in drive till you get enough money for the regear.
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I've seen people throw up the link to that calculator on a few different sites. Dam'd if I keep forgetting to save it. :doah:
 
www.diy4x.com has a gearing calculator under tech tips.

at 75 mph you would be turning 2070 rpm in od.

in drive you would be turning 2970 rpm to go 75.
 
I run that and it's fine. I can use OD on any highway. Yes, 4.56 would be better, but I think you should wait until there is some other reason to change the axles, gears or lockers. Running the 4.10 for a while only costs you what? A speedo gear?


Keep in mind that a lot of these trucks came with 29" tires and 3.08 gears, which is equivalent to 3.73 with 35" tires.
 
Blue85 said:
I run that and it's fine. I can use OD on any highway. Yes, 4.56 would be better, but I think you should wait until there is some other reason to change the axles, gears or lockers. Running the 4.10 for a while only costs you what? A speedo gear?


Keep in mind that a lot of these trucks came with 29" tires and 3.08 gears, which is equivalent to 3.73 with 35" tires.
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Thats true. I don't even know what my 'Burbs stock ratio is, never checked,but O/D works fine on the freeway with 32's.

I think I've concluded that I'm going to run 35's with the 4.10's for a year or so until I have the money to swap in a D60 front and re-gear to 5.13 for 38's. Any bigger than 38's and I might as well forget about O/D:haha:
 
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