I have a 77 F250 4x4. Looking for a bomb proof rear axle for tow/4x4 abuse. I plan to do a rear disc brake conversion on what ever axle I buy.

Any advice about D70HD vs D70U?

Any one pulled a D80 from a Dodge recently? (It has the Ford 8x6.5 lug pattern also)

Either of the D70s would be a good choice. If you're more concerned about wheeling ability then the 70U would be the one to get. The bottom of the housing has a nice smooth egg shaped contour. Just what many wheelers spend hours making their D60s and 14 bolts look like. The 70U has roughly the same ground clearance as a stock D60.

The D80 would defenitely be the beef but the housing is massive and you'd be dragging it around all over the place off road.

You didn't mention tire size but you'd have a tough time hurting even a D70 with anything less than 44"s.

My .02.......

x2 on the D70U. Those things are baby butt smooth and you only lose about a 1/4" of clearance compared to a D60.

x2 ON THE 70U

:jester:

I heard a rumor that they don't make a detroit for a Dana 80. I'd go with a D70. I have both the D70 U and HD. I can't tell much difference, but they do take different lockers. I've heard some of the newer D70's don't have 35 spline shafts, so you might want to consider that when buying one.

BTW I have some D70 detroits for sale. PM me if interested.

From what I've gathered, d70hd and d80 carriers are the same, except for ring gear bolt size, and some d80's use 35 or 37 spline shafts.

Get a GM 14 Bolt FF.

Get a GM 14 Bolt FF.

That was not an option doofas :flipoff2:

"Some Specifications and Facts on the 14 Bolt:

• Max gearing is 5.13:1
• Very limited locker selection
• 1.5 30 Spline Shafts
• Max Torque Rating: 6242 Lb-Ft of Torque
• Cast Iron Housing

Some Specifications on the Dana 70:

• Max gearing is a massive 7.17:1
• Excellent Locker Selection
• 1.5” 35 Spline Shafts
• Max Torque Rating: 8,000 lb-ft or 8,800 lb-ft for the HD
• Nodular Iron Housing

The two most significant of those are the gearing and torque ratings. You can gear a Dana 70 45% higher, and it is about 30% stronger than a 14 Bolt. Also to be noted is the different housings, nodular iron is much stronger (Ford fans know of the famed N marking on a 9” housing). It is also easier to weld to if you are doing an upper 4 link mount on the housing."

pwned

x2 on the D70U. Those things are baby butt smooth and you only lose about a 1/4" of clearance compared to a D60.
I felt that I should update this post. A buddy of mine that runs a D70U just dented the bottom smooth part. Don't ask me how, but it's got a real nice dent.