driveshaft interchangeability?

[kyle_22r]

i'm interested in putting a W56 tranny into my '79 pickup.  to save a bit of money, are there any driveshafts that i can use to replace what i've already got without taking them to the shop?  maybe one out of a longbed(i have an LWB truck)?

[WHITE_TRASH]

Everything should be fine.  Just remember that the drivelines will have the later flange pattern and 10 mm bolts unlike your diffs.

[kyle_22r]

so i take it the wheelbase is the same, the driveshafts are just shorter in the rear and longer in the front to make up for the longer tranny?

i saw an '82 tranny and case for $250 somewhere, i'm trying to contact the owner to see if its a 5 speed.  if that falls through i'll start looking for a W56 since i get paid this friday 

[Hyena]

If you are worried about the flanges just exchange them with the ones on the tranny now.

[BigMike]

First I'll tell you how you dont need to worry about the flanges, and then I'll tell you that its a bad idea.

This is not a flange issue unless you plan on using the t/case that came on the W56.
As far as the flanges go, if you want, you can simply use your stock '79 transfercase behind the W56. You will need to use a drimmel on the 4spd input of the transfercase to clear it to fit behind the W56.

Now that the flanges are compatible with your driveline, you've got a 2nd problem. The W56 is 4" longer than your L43 4spd. Depending on your suspension and amount of articulation, it would be best to get that drive line shortened 4". So its a bad idea to keep your stock 4spd transfercase since now you have the availability to run the stronger 10mm flange pattern. All you have to do is just drill out the holes on your rear pumpkin to 10mm since the pattern is the same.

Now you can get a replacement driveline that uses 10mm bolts which is what the stock t/case came with on the back of the W56.

So now we are on your question: Can you just simply find a stock driveline that exists that will be approx. 4" shorter than your LWB driveline and still bolt up? The quick and nasty answer to this is no. Before I became the owner of my truck, the previous owner had the truck converted from it's L52 5spd to a W56. I believe Rocky did the modifications to the crossmember and etc. for this, however he was not able to locate a stock driveline that would fit the new size needed. And believe me, we've got over 4 very large wooden creates out back with countless number of drive lines to choose from. He picked a whole bunch of 'em and started measuring them. Nothing would fit. So they took the stock driveline down to our driveline shop and got it resized and rebalanced for around $100-

Anyways, good luck and if you do this and happen to find a working stock line, please report it here!! As soon as I get my truck running, the first thing I'll do is put in tripple cases. Im hopeing to find a stock front driveline on an 3rd gen truck that will fit, but im sure it's gonna be too short. For sure I'll post some measurements and info on my thread when I get around to that point.

Regards,
BigMike