4.30 gears from excursion

THETANK01 · Feb 4, 2013

Thinking about taking 3.73s out and getting a set of 4.30s from an excursion. Anybody have an opinion on this. My reason for going this route is they are readily available at my buddy's wrecker yard. Has anyone else done this before. Btw im running 12" lift and 40s. 3.73s just arent cutting it i feel.

Sent from the drivers seat.

smokinstroker · Feb 4, 2013

If you don't buy these I would like to get the info

Copracr · Feb 6, 2013

they are a little too steep for 33's. I run about 2350 rpm at 70mph. I would run it through one of these online calculators to see where you will end up at cruise speed. Acceleration will be easier so thats really your only issue. Here's a calc for ya:
http://www.4lo.com/calc/gearratio.php

edit: sorry, I have 35's on the Ex and 33's on my ranger

Demon · Feb 6, 2013

Those would way better for 40s. I have 4.30s and 37s. It feels very much like stock.

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bigastrk · Feb 10, 2013

I would go with it. I ran 4.56's in my excursion when I had 38's on it. It was a little to low of a gear so 4.30's should be just about like stock in my opinion.

NEVRNF · Feb 11, 2013

4.30 and 37" tires will be the same as a 285 tire and 3.73's It is the perfect combo. I agree that 35's and 4.30 are not a good combo unless you are always towing heavy. That gives you about the same as a dually with 4.10 and stock tires.

steele86 · Feb 17, 2013

the calculator says 37 with 456's should run the same rpms as the 373's with my old 265/70/16 or am i doing it wrong?

bigastrk · Feb 17, 2013

steele86 said:
the calculator says 37 with 456's should run the same rpms as the 373's with my old 265/70/16 or am i doing it wrong?

I don't know if your doing it wrong or not but I know from first hand experience that 4.56's and 38's was like a stock truck with 4.10's or maybe just a tad lower.

steele86 · Feb 17, 2013

Mmm...... ok i think that's what I'm looking for thanks bud i just don't want the trans to work so hard

Layson · Feb 18, 2013

I had 40's with 4.30's. It is a great combo! If you tow alot then you might not like it.

I now am running 38's with 4.30's. It is great for towing and is closer to stock, but I actually don't like it most of the time. I got better mieage with the 40's and 4.30's over the 38's.

38's and 4.30's

I think this is 40's and 4.30's

steele86 · Feb 18, 2013

THETANK01 · Feb 18, 2013

Awesome. Thanks guys. Havent had the time or funds lately to do it. Hopefully ill get around to it shortly.

Sent from the drivers seat.

steele86 · Feb 18, 2013

Layson said:
I had 40's with 4.30's. It is a great combo! If you tow alot then you might not like it.

I now am running 38's with 4.30's. It is great for towing and is closer to stock, but I actually don't like it most of the time. I got better mieage with the 40's and 4.30's over the 38's.

38's and 4.30's

I think this is 40's and 4.30's

did you recalibrate your speedo? because my rpms and speed have not change but i know the truck is going 5 to 10 miles faster on the road.

Layson · Feb 21, 2013

yes my speedo is recalibrated. I think it was 1 mph off my gps.

steele86 · Feb 21, 2013

ok thanks for all the good info

Triple H · Feb 22, 2013

NEVRNF said:
4.30 and 37" tires will be the same as a 285 tire and 3.73's It is the perfect combo. I agree that 35's and 4.30 are not a good combo unless you are always towing heavy. That gives you about the same as a dually with 4.10 and stock tires.

Yes ^ You are spot on, that was going to be my reply as that is the combo I run.

steele86 said:
the calculator says 37 with 456's should run the same rpms as the 373's with my old 265/70/16 or am i doing it wrong?

Ditch the calculators. Try this for a comparison.:toast: Gather all your own data and utilize the math formulas. Do not use manufacturers or mathematical rollout for your equation. Instead, on a clean driveway mark ONE treadblock with oil - dish soap- whatever and drive the truck so that you lay down 2 spots after one complete revolution. Do this with whatever tire pressure you normally run with your truck empty or in its regular configuration of use. Measure center to center or edge to edge the distance of your oil spots. There's your dead nuts roll out for YOUR tires based upon wheel width, tire pressure and vehicle weight. Your calculations will now be 100% accurate in determining actual drive ratio, gear ratio and engine rpm.

Hope that helps you.

steele86 · Feb 24, 2013

What kind of mpg should i see with the 430s or the 456s with my 37s? Or would it change much

bigastrk · Feb 24, 2013

steele86 said:
What kind of mpg should i see with the 430s or the 456s with my 37s? Or would it change much

To tell you the truth if you are worried about Mpg's go back stock. I never watched mine because with a lifted truck Mpg's were the least of my concerns.