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3.73/700r4 people inside

G

Gaffed

1/2 ton status
Joined
Dec 26, 2006
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Location
Cantonment, FL
My question is how does your vehicle do around 70-80mph on the hwy with small hills? Obviously this depends on tire size. I'm running 32's. I've got 2.73's or so in the rear. sub-1500rpms doesn't cut it on the hwy in OD.

How do you like the 3.73 ratio for on pavement driving?
Would you recommend it? or go 4.10, 4.30 range?


Thanks,

Chris
 
It was nearly close to stock with 3.73 and 33's , considering my rig came stock with 3.08's and 10R15's ( 31's ) .

When I went to 35's and 3.73's it was doable , but it felt like when I went 33's on the original 3.08's .

I can do 70 around 2000 rpm on 4.56 and 35's .

I would do 4.10's with 32-33's , and 4.56 or 4.88 with 35's :thumb:
 
I've got a pretty much stock 350 TBI with 700R4, 3.73's, and 33" tires. If I could change it, I would have probably gone with 4.10's but the 3.73's aren't that bad. I just dislike how easily my 700R4 comes out of lockup at 70-75 mph. On a flat road with almost no headwind, my K5 cruises pretty effortlessly in lockup at 70-75mph but as soon as it gets the least bit hilly or there is a real strong headwind it has to kick out of lockup. I feel that if I were to get a bit more power out of my engine and/or I could adjust how easily the transmission goes out of lockup, then the 3.73's would do pretty well. Hope this helps.

-Wes
 
I run a 305/700r4 with 4.10's and 35's i was pretty happy with it. it would only run about 90mph down the highway tho due to the worn out motor. would really like to have had put in the 4.88 gears instead, but with tires smaller then 35's 4.10's would be ideal what i have run.

hope that helps from my small bit of experience
 
I run a 350\700r4 with 3.73 gears and 31" tires and the only time i can use overdrive is if the road is flat. Any time i hit a hill it falls flat on its face :mad: Until i pull it down into drive.
 
Thanks for the replys. Anyone got any experience of running a smaller than 35" tire with 4.56s? Also does anyone even make a 4.30 gear for the front 10 bolt?


Thanks,

Chris
 
ShiftyK5 said:
I run a 305/700r4 with 4.10's and 35's i was pretty happy with it. it would only run about 90mph down the highway tho due to the worn out motor. would really like to have had put in the 4.88 gears instead, but with tires smaller then 35's 4.10's would be ideal what i have run.

hope that helps from my small bit of experience
Click to expand...


I don't think it was the worn out 305 limiting you , mine is old and keeps on ticking . More of driveline loss , and drag ....... our trucks are like a huge brick with a little chunk off one corner:laugh:
 
Gaffed said:
Thanks for the replys. Anyone got any experience of running a smaller than 35" tire with 4.56s? Also does anyone even make a 4.30 gear for the front 10 bolt?


Thanks,

Ch ris
Click to expand...
:rolleyes: ran 4.56 with 35's now running 32 with the 4.56's.
 
Motive gear makes 4.30's for the 8.5 ( GM10-430 GM 10 Bolt 8.5" 4.30 Ratio Motive Gear ) . All 8.5's should be the same front , rear , and g-body .
 
The difference is in the housings , not the internals . They used the 8.5 on the A body cars in the 70's , the B body cars in the late 70's and 80's , certain G body cars like GN's , SS's , and 2+2's , and of course our trucks to today .

There are 30 spline axles after 1988 , but the gears should all be the same if its a 8.5 inch with "ears" on the lower of the centersection casting .
 
I've got a '90 V1500 Suburban, 4wd; tires: 29" diameter, P235/75R15; the thing came new with 3.73 10-bolt, 8.5" ring gear. I've switched the guts w/Eaton TruTrac carrier & 3.08 ratio sets from MotiveGear. I couldn't be happier. Used to be when I stepped on the gas at a stop light I could watch the gas guage go lower as the wheels screamed. All torque and no action. Higher top end, too, trans (TH700-R4) is happier, though I'm about to put in a B&M shift kit to tighten that up a bit.
 
Drove from Pensacola, FL to Galliano, La. tonight. Truck only kicked down out of OD twice. TQ Converter stayed locked the entire time except for the above instances. Thats with the crappy 2.73's or 3.08s whatever the hell is in it. Guess the road is a lil flatter than I thought.
 
pauly383 said:
It was nearly close to stock with 3.73 and 33's , considering my rig came stock with 3.08's and 10R15's ( 31's ) .

When I went to 35's and 3.73's it was doable , but it felt like when I went 33's on the original 3.08's .

I can do 70 around 2000 rpm on 4.56 and 35's .

I would do 4.10's with 32-33's , and 4.56 or 4.88 with 35's :thumb:
Click to expand...

I agree with pauly. I had 3.73 and 33's and it was fine but sometimes I wished for just a little bit more gear. 4.10's would be great for a 33, I think a larger tire would require a deeper gear.
 
Going to go 4.30's and eventually run 35s. I think that'll be the best mix between the 4.56s I want and the MPG I need.
 
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