Which gear ratio

[Jakedog]

Thinking of running 4:30 gears in the rear 9". For the front I checked the vendors and it looks like they jump from 4:11 to 4:56.
If I go with the 4:30 rear what ratio can I run up front?

Thanks.

 

[Deano]

I think your going to have to go 4.11 or 4.56 front and rear because I don’t think the make one that matches up with your 4.30 for a dana 44

 

[Broncobowsher]

4.27 front will match 4.30 rear

 

[sprdv1]

4.27 front will match 4.30 rear

This....


what size tires you running?

 

[Jakedog]

35`s with an np435. No plans to go bigger than 35".

 

[gnpenning]

4.27 front will match 4.30 rear

Have this combination on my 74. Been very happy with it.

 

[Apogee]

35`s with an np435. No plans to go bigger than 35".

With the NP435, you won't get the slip in the torque converter, so the gearing will feel a little taller than if you had a C4 as noted above by gnpenning. I would personally go 4.56 gears in your application since you have a 302, and just take the 6% gear ratio reduction and corresponding 6% increase in RPM at any given speed. At 70 MPH, the difference in RPM's between 4.56 and 4.30 gears is 3064 RPM versus 2890 RPM respectively, so not a huge difference IMHO.

Now if future plans include a 351W based engine, then I would consider the 4.30's, but only if my plans didn't include an OD transmission.

Tobin

 

[Timmy390]

My W loves my 4.11's and 33's......it's all about the cam!!!! I bet it would like 4.30's even more....

35's I would go 4.56.........Get a cam that like the RPM with gear/tire combo.

Tim

 

[blubuckaroo]

My W loves my 4.11's and 33's......it's all about the cam!!!! I bet it would like 4.30's even more....

35's I would go 4.56.........Get a cam that like the RPM with gear/tire combo.

Tim

Right Tim^^^
Gear ratio and cam numbers together will make or break your driving experience. They've got to work together, or you'll be leaving lots of performance on the table. You can't just start bolting bunch of cool parts together, and expect it to work.

 

[R0kcrwlr]

I see Jakedog has NP435 trans so my question is how about if you have a C4 with 35" tires but probably 34" once one vehicle I assume. I have been in the same debate between 4.56 and 4.30 gears. I currently have a bone stock 302 but will be pulling it out soon to refresh it and research what cam I can put in it to help the low-mid end performance. Any thoughts on a recommended cam or best bang for the buck would also be appreciated. Thanks.

 

[Broncobowsher]

I see Jakedog has NP435 trans so my question is how about if you have a C4 with 35" tires but probably 34" once one vehicle I assume. I have been in the same debate between 4.56 and 4.30 gears. I currently have a bone stock 302 but will be pulling it out soon to refresh it and research what cam I can put in it to help the low-mid end performance. Any thoughts on a recommended cam or best bang for the buck would also be appreciated. Thanks.

Still 4.30s. Both transmission still have the same top gear 1:1. The C4 will have a few hundred RPM of convertor slip at speed. Those gears will work with a stock or a mild engine build just fine.

Once you get into an overdrive transmission is when you go a lot lower in gearing so the OD is still usable.

 

[LSharpNM]

It depends on your engine and intended usage. I personally would stick with 4.10s with a 302/5.0L, NP435, and 35" tires if you plan on doing much highway driving at or above 65MPH.

I have run that combo in a couple different rigs now and it works pretty well for not having an overdrive tranny. 4.10 vs. 4.56 in the axle really won't make a noticeable difference on the trail when it comes to crawl ratio, but will make a good deal of difference on the highway.

I have also run 5.13s on another non overdrive rig on 35" tires, so, I have been on both ends of the spectrum. If your 302 is healthy, I would definitely stick to higher axle gears. The rig I had with 5.13s had an anemic engine so it needed the power. I went from 3.73s to the 5.13s, and with the 3.73s, I could only hold interstate speeds in 4th on flat ground. With the 5.13s it could pull modest grades in 4th, but my highway fuel mileage dropped from ~14-15MPG to 11-13MPG, and it was really noisy (the glasspack muffler certainly didn't help).

Just my 2¢, but these old smog-era 302s don't like cruising much above 3,000RPM and they have a pretty low power band. I don't feel there is much to be gained by revving one out unless you have some better heads and a cam.

 

[Jakedog]

It depends on your engine and intended usage. I personally would stick with 4.10s with a 302/5.0L, NP435, and 35" tires if you plan on doing much highway driving at or above 65MPH.

I have run that combo in a couple different rigs now and it works pretty well for not having an overdrive tranny. 4.10 vs. 4.56 in the axle really won't make a noticeable difference on the trail when it comes to crawl ratio, but will make a good deal of difference on the highway.

I have also run 5.13s on another non overdrive rig on 35" tires, so, I have been on both ends of the spectrum. If your 302 is healthy, I would definitely stick to higher axle gears. The rig I had with 5.13s had an anemic engine so it needed the power. I went from 3.73s to the 5.13s, and with the 3.73s, I could only hold interstate speeds in 4th on flat ground. With the 5.13s it could pull modest grades in 4th, but my highway fuel mileage dropped from ~14-15MPG to 11-13MPG, and it was really noisy (the glasspack muffler certainly didn't help).

Just my 2¢, but these old smog-era 302s don't like cruising much above 3,000RPM and they have a pretty low power band. I don't feel there is much to be gained by revving one out unless you have some better heads and a cam.

I went with the 4.56. I just finished the install a couple of days ago. I took a quick drive yesterday and I really like feel of this transmission, tire, and axle combo.

 

[LSharpNM]

I went with the 4.56. I just finished the install a couple of days ago. I took a quick drive yesterday and I really like feel of this transmission, tire, and axle combo.

Glad you are happy with the 4.56s! Out of curiosity, what ratio did you come from, and what does your usage mix for your Bronco look like? Do you cruise much on interstates at 70+MPH?

Like I mentioned, I have had the opportunity to drive many different setups, so I have a pretty good feel for what I would prefer, but many other members haven't,. I think it would be good to give the details I asked about so other members can get a feel for whether 4.56s would be right for them as well. Unless you are setting up your gears yourself, gear swaps are to expensive to screw up the ratio the first time around

I am not against using 4.56s with 35s and an NP435, but I think if you anticipate doing much interstate driving the 4.10s will serve most people better. At 75MPH you will be turning ~3,300RPM with 4.56s vs. just under 3,000RPM with 4.10s.

 

[Jakedog]

Stock 3.50 gears.

The longest highway trip I'm planning on is about 200-250 miles. That will be once a year to go to the wild horses roundup(at least once).

I do plan on going to the central California coast (about135 miles) at least once in the summer months. Those would be my longest highway trips.
It won't see 75 mph. 65 tops. Other than that it would be like a d.d and all around cruiser.
This combo works for my needs.

My dad had several old manual shift vehicles, but one of his favorites was a 66 f250 with a 352 and a 4 speed. He carried a cab over camper for our camping trips and a welding machine and tools for work.
That truck traveled all over California.

I plan to use the bronco as needed.