'74 Gears

[Carlson]

Help... I'm rebuilding a '74 Bronco with a 351 (automatic). It's all coming together well, but when I drove it home after buying it, I noticed that it was geared way too low (for rock crawling)... I bought it from the second owner and he was unsure, but thought it had a shift kit and lower differential gearing. As the project comes together, I think I'd like to keep the shift kit, but swap out the low diff gearing to get it back to stock gearing (increasing my top speed and decreasing the "tire chirping" between gears). Can you tell me 1) what the stock rack and pinion tooth count is and 2) if swapping back to stock is possible? Thanks...

 

[S_bolt19]

Oh yeah, swapping back to stock gears is possible. It just costs money /emoticons/[email protected] 2x" width="20" height="20" />

To find out what stock gearing is, look at the rear end and somewhere on a 3rd member bolt there should be an aluminum tag. This tag will tell you what original gearing was. If the other owner didn't take that tag off, you will be able to tell what they were.

The other thing you could do is to look at the VIN number. Write that down and then check this website...it is BroncOhio's club website and it has all the VINs decoded for every year EB.

http://www.broncohio.com/tech/ebvins.html

 

[Bandit]

&lt

Help...  I'm rebuilding a '74 Bronco with a 351 (automatic).  It's all coming together well, but when I drove it home after buying it, I noticed that it was geared way too low (for rock crawling)...  I bought it from the second owner and he was unsure, but thought it had a shift kit and lower differential gearing.  As the project comes together, I think I'd like to keep the shift kit, but swap out the low diff gearing to get it back to stock gearing (increasing my top speed and decreasing the "tire chirping" between gears).  Can you tell me 1) what the stock rack and pinion tooth count is and 2) if swapping back to stock is possible?  Thanks...

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Carlson,before you go taking out low gears you might wish you had later,you might want to look at the chart that Bronco Driver Mag had a few issues ago.It had the gear ratios, all set up with the tire sizes,and cross checked with the Rpm.It also gave you a great idea,comaring what range it would put you in...ref power vs towing vs rockcrawling and fuel economy.Very usfull in picking your rear end ratio.You know you could also go up on your tire size to solve too low a gearing.If you find out what gear ratio it is and still want to get rid of it let me know I might be interested in getting it off you,if its at least a 31 spline.

Good luck;

BANDIT...awesome '73

 

[Leo]

First of all, these guys are giving good advice. Find out what you have first.

Second, you should be making money here! Don't just go and get regeared! It's expensive, and you have another option. That option is to trade someone for thier stock front and rearends; "AND," you should also be able to get a little extra money, too! If you have the desireable 4.56 and lower (higher numerically) gears set up already, "you" should be making money in this deal. Food for thought.

 

[Broncoholics]

Count to number of tire rotations to number of driveline rotations. This will tell you the ratio close enough. Most want the lower gears for off road use, better take it to the hills before you decide. You can always get larger tires. This will reduce the RMP's, add more clearace and of course it looks better.