Rear Diff gear question

[giannetti]

I have a 74 EB and I want to change the gears in the rear diff so that my Bronco is better suited as my daily driver, but also so I can take it off road-racing some day(baja, trophy, etc). I'm not sure what gears are in it now, but I do know that they are suited for rock crawling. I plan on throwing 35's on it as well. Anyone have any suggestions? Thanks.

 

[broncnaz]

You need to determine what gears you currently have and what tire size you have now. As for a gear set that will work for a daily driver and a racer its hard to say until you figure out what setup you are going to run a racer setup may be very different from a daily driver setup but then again it could be close. We really need to know what your setup will be ie engine, tranny, tire size ect.

 

[DirtDonk]

And if you've already determined that you're going to run 35 inch tires, that limits your choices to just a few. Probably between 4.10 and 4.88, but that could still change depending on what transmission and what your daily commute is like.

Oh, and you do realize that you can't put it in 4wd if you just change the rear gears. You have to change both before you can go back to using 4 wheel drive. You may already have known that of course, but it was worth mentioning.

Paul

 

[wildbill]

;D ;D ;D With 35" tires I woul suggest going with eather 4:56's or lower or you will have a dog gear wise good luck. Bill %)

 

[starkypdx]

I have 4.10" in the 77 and run 33" tires. When I put the 35" booogers on it's a big difference. I wouldn't go anything less than 4.56.
With that experience in mind I just ordered 4.88 for the Project: Brown Hornet!

 

[giannetti]

I'm going to be putting the 35's on at the same time I put the new gears in. As for the engine I'm running the 302 and will be using it for quite some time. I would like to one day throw in a 351c or 351w, but as I'm a college student that's not going to be any time soon. I'm using the stock 3-speed AT. Again, I'de like to have a 5-speed AT with overdrive built some day, but that also won't be for some time. I guess for now I should focus more on making it just a daily driver since I also need to get a new suspension before it does anything crazy off-road and full-time college and part-time work unfortunately doesn't do much for my Bronco budget. As for the amount of driving it gets, I take it every where. I'm thinking 35's because I've been reading up on other people's EB Baja racer builds and a lot of the mseem to use 35's. Seeing as I'm a noob and my Bronco isn't going to be stricly JUST a racer, do you think 33's would be a more practical decision for what I'll be using it for or does it not make that big of a difference? I hope this helps give you all a better idea of where I'm coming from. I apologize in advance because this is my first EB so I really appreciate all of your feed-back and advice. Thanks a ton again!

 

[Broncobowsher]

For 35's and no overdrive being pushed through a 302.
That is actually a fairly good load on the truck and will take some gear to move. My feeling is either a 4.30 or 4.56 ratio. IF you already have 4.10s now I would consider just leaving them in there to save money.

You mention that it already has gears better suited for rock crawling. Take a moment and check out the tech section. There is an easy way to check gear ratios with some tape and string. Run that check and let us know what you find. There is a good chance that we will simply tell you to leave it alone.