(TOM) 727/D20???

[Iron Horse]

1) Is it possible?

2) Is it worth doing?

3) What would need to be done to a late 80's wag for this swap?

4) What are the D20's specs.?

[ December 03, 2001: Message edited by: Sitting Bull ]

[JohnnyJ]

Possibly, but I recommend using a Dana 300 instead.

Putting a Dana 300 on a 727 is much easier since the D300 and NP transfer cases have the same bolt-pattern and 23-spline input shaft.

It also has a lower low-range at 2.62:1 vs the 2.03:1 for the Dana 20.

The D300 is known for being strong, but Advanced Adapters sells a stronger tailhousing that makes it comparable although still weaker than an Atlas 2.

Now for the cons:

First, both the Dana 20 and Dana 300 are passenger side drop. With either case you would have to swap in a 74-79 front Dana 44 (or similar passenger side drop front axle).

Another option for the D300 is to buy/make a clocking ring to allow for use with driver's side drop.

Another con for the D300 is that it does not like flat towing. Generally, most will leave the t-case in 2wd and pull the rear driveshaft to prevent blowing up the case.

The final con for a D300 is the price. Since they are a good part with a good reputation with parts available to make them stronger and easy to adapt to vehicles, they are getting pricier.

[Addition]
The D300 also has a 4:1 low kit available, making it even more desirable. The D20 only has a 3.15:1 low available.

So the use of a D300 with clocking ring, modified tailshaft, and 4:1 kit would yield a similar case to an Atlas 2 with no need for swapping the front axle.

The Atlas 2 is also an option to use with the TF-727 due to its use of the NP bolt pattern and input spline.

[ November 08, 2001: Message edited by: JohnnyJ ]

[porkchop]

<BLOCKQUOTE>quote:</font><HR>Originally posted by Iron Horse:
1) Is it possible?<HR></BLOCKQUOTE>

It is possible with a pricey adapter from Advance Adapters. I don't beleive Novak makes one.

2) Is it worth doing?[/QUOTE]

It is not worth the cost of doing it. If you want the cast iron gear driven case you can swap in a D300 with out an adapter.

3) What would need to be done to a late 80's wag for this swap?[/QOUTE]

Like I said earlier you would need the pricey adapter and you would have to swap the front axle so it would be a passenger side diff.

4) What are the D20's specs.?[/QUOTE]

The low range on a D20 is 2.03:1 on the D18 it is 2.46:1 and on the D300 it is 2.61:1 (I am not positive on the D300). It would be a lot less trouble and time to swap in a D300. I am sure I missed a few things. This is the basics though.

[Joe J-Truck]

What did D300's come in?

[JohnnyJ]

1980-86 CJs are the easy find

I think they came in some Scouts, but I don't know all the info for that.

[Cecil14]

Will a Dana 300 bolt to a T-176? I know about the front axle, gonna swap that anyway, but the bolt pattern and input shaft are the same?

Thanks,
Anthony

[JohnnyJ]

It should, since the T-176 had a NP transfer case behind it.

The big problem is that the D300 and NP transfer case require different front axles, or the use of a clocking ring to run the D300 upside down.

[Iron Horse]

Will a D300 run upside down if clocked? Would you have a lubrication problem doing this?

Andy

[Cecil14]

If/when I swap to the D300 I'm going to swap in some real axles anyway. hehe, those little D30/35s just don't cut it.

Thanks,
Anthony