axle ratio 3.73 4.10

How much of a difference is there between a 3.73 and 4.10 axle ratio. I'm looking at a chevy 2500 with a 454. I was told to find out which axle ratio (GT4 or GT5) the truck has. If it has A GT4 is it still a monster? Is there a huge noticible difference between the 3.73 and 4.10?

Reply to
lucascjcabe
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Greetings,

There is not much difference between the 3.73 and the 4.10 rear ratio on the truck you are looking at. I suggest that you find the towing specs for that truck and compare what the tow ratings are for the different axles - I think you'll find it to only be about a 1000 to 1500-pound difference in capacity or so (with a towing capacity being somewhere around 10 - 12,000 with a WD hitch - but these numbers are only my estimates). If you are to do a lot of towing or tow at or near the upper rated capacity I would suggest the 4.10 for slightly better capacity and ease on take-off as well as a better mechanical advantage for pulling a heavy boat out up the ramp, but if you tow less frequently or less than max capacity then the 3.73 would be fine and give you a slightly higher top end and slightly better MPG on the highway.

Of course the use of oversize tires with a bigger diameter will also affect which axle you will want as well, which will also depend on the overall set-up of the drive train. As a general rule with all else being the same, you may want the 4.10 with larger diameter tires to get the same final ratio as the 3.73 would give you with stock size tires, whereas the 3.73 might cause you to feel like you are losing power because the final drive ratio with the larger tires may not be in the optimal power range for the motor under load - but I'm sure that there are others here who could more adequately give you advice on this type of set-up rather than me.

Cheers - Jonathan

Reply to
Jonathan

There can be a lot of difference depending on the year (which determines if it is a THM400 3 speed or a 4L80 4 speed), tires size, loads and altitude. I would suggest a 4.10 is 92 or newer with a 4L80 and a 3.73 if it is older since it will have no OD. If you go the the first link below you will find a on line tire size/axle ratio calculator that can take some of the mystery out of it for you. The second link has the actual gear ratios used in several GM trannies.

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TheSnoMan.com

Reply to
SnoMan

I found a big difference in my gear ratio. I own a 1974 Chevy K-10. With my

8" lift and 38.5 Ground Hawgs I could only push about 60mph @ 3000rpms. I went to 4.56 Yukon Gears and now it does about 85 before the bias plys start shaking.

Reply to
Dave
3.73 gears, 3000rpm, and 38.5" tires...and you only got up to 60mph???

Try taking it out of 2nd gear. :-)

~jp

Dave wrote:

Reply to
Jon R. Pickens

I think the point he was making is that it would not pull drive either or his tranny is getting weak and slipping a lot.

----------------- TheSnoMan.com

Reply to
SnoMan

The gears did help...later a new tranny and new CV rear driveshaft that decided to snap from the driveline angle.

Reply to
Dave

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