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Need Drivetrain Opinions

T

talldogg

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Okay, I'm planning the first phase of my '75 K5 build up. Starting with the drivetrain. Here's what's in it now: a dead small-block (munched piston), a rebuilt TH 350 (only 13k miles on it), and the stock T-case. I have a 454 waiting for it, and had planned on mating it to a 700 R4, because of the OD (lots of freeway driving), but I'm having concerns about it handling the big block. My friend is offering me a high end TH 400, cheap, but it's for a 2WD truck. My ideal set-up would be the 454, with a 700 R4, and a PART TIME transfer case. Starting with the 454, what would be the ultimate, bullet-proof drivetrain? How strong is a 700 R4? Is there a significant gain from the OD? How compatible are these trannys (350, 400, 700)? What about the T-case? Pleeese, what do you all think?
 
I think the ultimate bulletproof set-up would be: TH400, NP205, Dana 60 front, 14 bolt FF rear. If you match your gears to the tire size and type of driving you'll do the mileage won't be that bad. If you can't aford the D60 a Dana 44 HD will also do quite well unless you are running tires bigger than 35". Just my opinion.


Rene 81 Jimmy,350,SM465,FF14 bolt,HD Dana 44,3.73's,4"susp.,35"Grabber MT's,body in progress
 
Whats the difference between a Dana 44 and a Dana 44 HD? I imagine the HD stands for "heavy duty, but what exactly makes it HD? Thicker axles?

I was always told a Dana 44 was a Dana 44 and didn't know there were different models other than a 6 lug and an 8 lug.

Thanks

Mike
tongue.gif

1982 GMC Jimmy - <font color=green>Emmett</font color=green>
http://emmett.coloradok5.com
 
454(you have)
TH400(you can get)
NP205 is definetly the strongest (but if you already have a 203? it will be fine).
14bolt FF 8lug for the rear (but what do you have and what do you want to do with it)
and a D60 for the front (and again it depends on what you have and what you are going to be doing)
I don't care what anybody says the 700r4 is not a great tranny most of the time you can never even use the OD anyway. A good one cost WAY too much and a cheap one is WAY too weak! a good 400 is practically Bulletproof!
tRustyK5 is right about the gears/tire size=gas mileage!
 
Well, this is my *opinion*....

The most absolute bulletproof GM parts you can stick in at a 4-speed manual (SM465) and an NP205 (part time, all gear). But it sounds like you want an auto :)

Most built aftermarket TH700's i've seen are rated to only 450 lb/ft of torque, which any 454 can pull if in good tune, even stock. I would go with the TH400, which stock will pull 500 ft/lbs, and if you happened to find one with an NP203 (full-time) tcase, you could stick on an ORD doubler!

Squash
http://www.trailrunners4x4.org/users/realsquash
 
I'm not sure what the ORD doubler is. It seems the TH 400 is stronger than the 700 R4. I would have to play with the gears to get the mileage I want. Remember though that the TH 400 that I can pick up cheap is for a 2WD truck. Are they interchangeable? My friend said it depends on the T-case, on whether or not they're "married"? I really don't believe him. I thought that there is a clear difference between a 2WD and 4WD tranny. Thanks.
 
If you need a heavy duty O/D trans go with a 4L80E or an NV4500 and be prepaired to spend some cash. The other option would be to use the TH400 or SM465 and gear the diffs a little high. If the NP203 is still in there you could convert it to part time.
Execuitioner, Emmittolgy & tRustyK5, I don't think GM ever used the Dana 44HD, I am not positive on that but I have never seen one listed. Dodge uses them on their late model, 95-up, 3/4 ton diesels(not sure about the gas trucks) but the diff is on the wrong/driver's side. Exe, if you are back in GA, it was hard to tell from your profile, we can go up to Cherry Log and look at my friend Steeve's. I need to take some more measurements to see if it will work on a late model Chevy. Jim.

BigJBear '80 GMC
http://www.bigjbear.coloradok5.com
 
I know that there were two different kinds of D44's that GM came out with for their 1/2 ton trucks. But none were called D44 HD(that I know of). Anyways, Dana44 that came with 69' to 72' K5's (and early model 73') were about 30% weaker than the D44's that came with later model 73's and up. This was b/c of the closed knuckle vs. the open knuckle. Forgot which was which, but I'll edit this post when I can remember. (soon I hope, b/c I know you Executioner, just want the HARD facts right, LOL) So basically what I'm saying is there are two different types of D44 that came with GM trucks. If you want to swap in a D44, (which I wouldn't since you have a 10 bolt up front and they're almost equal in strength), then look for a 74' and up D44 to be safe.
Boss
 
The Dana 44HD also has thicker wall tubing (.500") than the half ton version. You'll have to take my word for it. I swapped out a half ton Dana 44 for the 3/4 ton Dana 44HD.


Rene 81 Jimmy,350,SM465,FF14 bolt,HD Dana 44,3.73's,4"susp.,35"Grabber MT's,body in progress
 
the 72 and earler D 44 had smaller bearing in the spindel. and used smaller U-joints than later years, spindels and hubs changed at the end of the 72 year, then hubs changed in 79, the first changes was to bigger bearings Inner and outer, and to a thiker spindel wall. the 2nd change was just to the inside bearing. A use the same lock nut and hub and the 10 bolt also used tha same spindel and axel.

There were 2 axels shafts used in 67 to 73, one was the 1/2 ton , the other was the 3/4. The 3/4 was the HD 44. all that changed was the outer hubs and the brake's,the size of the u-join and the thickness of the axel shaft. in 73 up truck the axel shaft was the same in all 1/2 ton or 3/4 trucks.

there is some thought that Dana used diffrent tubes in diffrent years cant find out if this is true or not, yet there is vairances in the tube inside ID even from side to side on the same axel.

The 44 is stronger than the 10 bolt only in that the 44 does not have the window in the cairer for the axel c-clip. no there not used when in the front but are used in the rear and the 10 bolt is the same one as used in the rear. If you install any type of looking dif the ones for the 44 will be stronger than the ones for the 10 bolt becuse of this. I the case of the ARB's there not even makeing the 10 bolt (or the 12) lockrs due to the lack of the 4th spider gear cuseing the locker to be easyer to damage. ( ARB is talking of a new soon with 4 spider for the front but dont look for it soon)

I understand the jeep thing I drive a BLAZER!!

Ken
 
Basically, some of the earlier (early '70s?) 44's used the smaller 260-X u-joints (the same size used in the model 30 front axle) and are very weak. Most of the later 44's used the 297-X u-joints which are much stronger. The reason I say this, is that in my experience the axle u-joints are the weak spot when using the 44's or 10-bolts for fourwheeling.
 
Very ture and if the axel shafts have ever been replaced they most like have been replaced by the later larger U-joint.

I understand the jeep thing I drive a BLAZER!!

Ken
 
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