OK,...What to do?

Currently I have a BB 9" in the rear (4.10's) and a 44 in front. all with Drum breaks and 33" tires. A 2" body and a 3.5" suspension. My plans for the 73 are a 5.5 inch suspension, 38" tires 2" Body (completed) 95 5.0 EFI (In progress) and from there I am looking for opinions as to the set up.

The Diff's need to be gone through and breaks changed (obviously). y question is should I just find full width and invest the $ there or should I put the money into the 9" and the 44 and hope they live a while?

Also, I am wondering if I should relocate the rear shocks in ward or what? I do not want to cut into the inner fender wells and loose room inside. (sleeping area)

I would love input, suggestions, pro's and cons to all.

Thanks,

Mike

 

This all depends on what you want to do Mike...

I'm going through the same thing right now. A big bearing 9" can take a lot of stress...more if it's 35 spline (stock is 28). 28 spline is fine for a good majority of off-road and all highway use under 400 HP. Over 400 HP, you'll want to invest in higher splined axles. As for the front, Dana 44's are tough, especially for the Bronco as the truck's weight doesn't even come close to the axles capacity. Mine are a 30 spline front axles (stock). You can get higher splined front axles, but if you're doing that, go for the full on bigger u-joint axles as the stock u-joint is the weak link in the front end.

You'll also have to think about gearing, what's the final drive ratio of the tranny?

My setup has an A4OD with a final drive of .71:1, my xfer case is 1:1 and the gearing I'm doing is 3.93's bolted to Detroit TrueTracs front & rear, all sitting atop 33's. I'll be able to cruise down the highway at 80 MPH with a tach reading of around 2300 RPM. Crawl ratios need to be figured as well...

Stock Dana 20 in my '76 has a 2.34:1 reduction, with the gearing mentioned above, at 600 RPM I'll be able to keep a leisurely 2.67 MPH...

I have a nice excel spreadsheet that figures this stuff all out for you...email me if you want a copy.

Like I said before, it all depends on what you want to do with the truck...and while you have the pumpkins open, consider putting lockers in...if you think about doing it later on, you'll have to pay to have the gears setup all over again.

Good luck

 

It really depends on what you're planning on doing with it. Are your going to wheel it, or is it going to be primarily a pavement pounder?

At bare minimum with 38's, I would upgrade to 31 spline axles in the rear, keep 30 spline axles in the front and upgrade to large u joint alloy axles. And since you need some brake work anyways, I would go ahead and put disc on the front end if you don't already have them. If you wheel it hard, the 44 is going to be the weak link with 38" tires. You might run it for a while with those upgrades and see how it holds up. Gearing and differential options also depend on what you're doing with it.

The popular way to go for rear shock mounting is the canted inboard setup. Seems to offer the most shock travel without going up through the floor 2 feet like an off road truck. The rear shock hoop setup like what Wild Horses sells (where you have to cut the wheelwells a little) isn't a bad setup, but I have heard that the inboard setup offers more travel, and better wheel control.

Jason

 

I WILL see off road duty. Being in Northern California I will be hitting the Sierra track, the Rubicon, and Berit's lake (sp) as well as others. The problem is I would also like to be able to drive it 700 miles or so and hit places like Glamis and others.

There is a constant debate around my house. My roommate insists that the 44 will never last and I will not be able to build it to do all the things I want, and if I do It will only be able to do them half a$$ed.
I forgot to add that it currently has a built C4 with a 900 rpm "low loc stall" as the builder likes to call it with a Dana 20. I was thinking of going the cold duck or the Atlas II route also.

So I take it that the 9" is adequate with 31-35 spline rear axles and a good diff?

How about this

Rear
9" with welded axle tube support, Ox or ARB in the rear with 31-35 spline axles. Inboard shock mounting with Bilstein w/remote resivar shocks, wrap trap (front and rear)

Front
Locker, 30 spline axles, WH Hoops, Dual shocks, disk breaks (w hydraboost set up), and new locking hubs.

What all is involved in upgrading to the large u joint axles?

Thanks guys, The Bronco is fast becoming my newest obsession!

 

Sounds like a winning setup. However, I would put the selectable locker up front and run a detroit in the rear. Ideally install a selectable in both, then you have less wear and tear for normal driving. I wish I could tell you about upgrading the front, but I have stock axles all the way around still!

J.D.

 

Here is my suggestions:
For the rear- start with a 77 9" big bearing housing, since you need to upgrade axles anyways I would go with 35 splines with a Detroit Locker.

For the front- the 44 can last in the front depending on how hard you wheel. I would upgrade to the large u joint shafts (Warn or Moser recommended) with CTM u joints. If you stay with the 30 spline inners, the new axles will slide right in with no modifications. Up front is where I'd spend my money on an ARB. Some guys have had decent luck with 44's in front with up to 38" tires. And then there are guys like me that take it really easy and break alloy axles with 35's, so theres a little luck involved. Run it for a while. If it is constantly breaking, have a 5 lug Dana 60 built.

For gearing, I would go no higher than 4.88. Ideally for wheeling, I'd like 5.38's with 38's. This will be a bit high revving on the highway, but you also need to overcome the mass of the larger tires.

Also, since you have plans of highway driving to get to some of these spots, I would recommend an OD auto. Probably the best route in terms of performance and durability would be the 700R4. It has a lower 1st gear than both the C4 and the AOD, and it can be built to withstand lots of abuse. There are adaptors available to mate it to the 302 and to the stock D-20. Or you can bolt an Atlas directly to it. With 5.38 gears, your cruise RPM at 65 would be about 2200.

With those tires, you'll probably want to do some steering upgrades for the rocks. I would recommend locating the tie rod over the knuckles and get one of the DOM tie rod kits available. I've heard that the Chevy 1 ton tie rod ends are the best way to go for longevity. I would also recommend having the steering box built and ported for ram assist to make steering in the rocks trouble free. And upgrade the p/s pump to a saginaw with a remote reservoir to help feed the steering and the hydroboost.

Jason

 

Thanks Jason, Sounds good. I will add your recomendations to the list.
With the Atlas are you talking about a 2200 rpm cruise with the 700R4 or just the C4?

I may be alble to get 3/4-1 ton running gear for CHEAP or mabe even free. "IF" that happens I may have to re think the set up.

 

That cruise RPM was with the 700R4. The C4 would be right around 3K. Both transfer cases are 1:1 in high range, so they would be the same.

FYI, most 3/4 tons have Dana 44s in front. The only strength you would be gaining would be thicker axle tubes and 8 lug wheel patterns. If you want to go this way, look for a 78-79 F250 snow fighter (and most camper specials that I have seen), 78-79 F350, 86-97 F350 and some 99 up Super Dutys for a Dana 60. Or you can have a custom housing built to your specs.

Your welcome,
Jason

 

You didn't mention what HP range you're looking at. If it's over 450, I'd rethink the Atlas, even for a smaller vehicle like an EB. For as much as they're asking for an Atlas, you could get a A4OD built and not get flack for using Chevy parts in your buildup. The big hangup is gonna be using the stock D20 TC.
As for the strength of a D44 in the front, I'd upgrade watch out for what you're buying. Would you rather break an inner/outer factory shaft, or break the differential cuz the hi-strength shafts and u-joints are strong?
If you're gonna go full-width full-size axles, just get wheels with a 4 inch offset. That'll bring the tire in enough that it won't look too goofy. I think the full-size axles are about 7 inches wider than the EB's.
A 33-spline axle with a Nodular case and detroit locker or arb (JUST SAY NO to OX lockers!) would be good for 600 hp on 40" boggers, so I've been told, so there's no reason to go with 35-spline, unless everything is the same price. Either way, you'll never break either one.

 

Why no for OX?

 

Not me, but I've heard bad things about the manufacturer (bankruptcy) as well as tech and product support. The concept (mechanically actuated locker) is a BRILLIANT idea, but if there's no manufacturer support, then having one and it breaks makes just about as much sense as restoring an Edsel.

 

The reason most go with 35 instead of 33 spline is they are more common and on the shelf. And the availability for differentials is better.
Most probably wouldn't need anything over an alloy 31 spline, but some overkill is good, especially with 38" tires.

I haven't heard of any strength issues with the Atlas II. I know of many behind high horsepower stroker Windsors in EB's. And I've seen a few of them in full size trail rigs before the 203/205 doublers became popular.

I don't think it matters what brand the parts came from as long as it works good and is reliable. The fact of the matter is that the 700R4 has many advantages over the AOD. Cost to build, strength, gearing, etc. About the only thing on my Bronco that is still a Bronco is the frame and the hacked up body. Some of it isn't even Ford anymore.

Jason

 

Yes, I had heard the same thing about OX, but I think they have better management in there now and the company is improving. They must be to introduce their own line of u-joints. I don't think I'd shy away from an OX locker now. If you have any question, just ask how the business is doing before you order.

J.D.

 

the HP is stock at the moment (225), it will soon be around 280 or so.

then the first rebuild will probaly be either to a 351W or a 318. either one will be about 400hp as long as they stay NA. I "MAY" add some nitrous for kicks and some hill's and sand down the road.