Driveshafts

[Jonathanlackey]

I am keeping the 350 sbc and the th350 that were original just replacing the np203 transfer case with a np205 transfer case and added a 2.5 inch leveling kit. When I looked it up I got mixed opinions on whether you can or you can not use original length drive shafts. One guy said he has a 205 with a 4 inch lift and works fine with original drive shafts. While others say 205 with stock height and had to have customs made or a 203 with lift and had to have customs made. Just wanted to ask for more opinions?

 

[tarussell]

I am keeping the 350 sbc and the th350 that were original just replacing the np203 transfer case with a np205 transfer case and added a 2.5 inch leveling kit. When I looked it up I got mixed opinions on whether you can or you can not use original length drive shafts. One guy said he has a 205 with a 4 inch lift and works fine with original drive shafts. While others say 205 with stock height and had to have customs made or a 203 with lift and had to have customs made. Just wanted to ask for more opinions?

I don’t have any solid dimensions to give ya but I can tell ya some facts from years of lifting and modifying old squares.
The front shaft on a TH350/203 set up is several inches longer than a TH350/205 set up.
As for the rear the 203 rear yoke dimension is farther back than a 205 when both cases are hooked to a TH350 so the shafts are different lengths as well.

Be cautious with tales of things fitting perfectly with no issues - it might very well be true but in more cases than not it just doesn’t work out that way.
People sometimes don’t really know what parts were involved or sometimes parts did bolt up but were not a quality or ideal way to go.

Take your own measurements off of your own truck once the T-case and lift are completed and then you’ll end up with proper slip yoke engagement on both shafts.
Different manufacturers, weight distribution, spring fatigue and sag along with other modifications all come into play.
A little more hassle and time consuming but ya can’t argue with the results compared to word of mouth, tall tales or guess work….

 

[Wes Harden]

I am gonna say the rear drive will be to short converting from a 203 to a 205. I did this conversion myself many years ago. I had 2 77 k20 suburbans 1 sm465 np205, and the other started out as th350 with np203. Switched the 203 for 205, and used the 2 piece factory drive shaft from the sm465/np205 combo. I didn't get a front driveshaft in that truck till July this year.
Best to get the swap and lift done and measure.

 

[tarussell]

Disclaimer for taking other people’s advice on things that fit or not - @Wes Harden is one of those that are in the “He knows what is what and what he’s talk’n about” category .
Sometimes folks mean well but are just plain wrong, some just think they know stuff and are dangerously throwing info out there and others are well educated in the area interest and are well equipped to give and spread knowledge - Wes is in this last category.

 

[Bent77]

About once a year I have a nice conversation with someone about why one of two things has happened:

1) my driveshaft looks long enough but I have weird vibrations
2) my driveshaft looks right but my transfer case is now broke

 

[obijuank5]

Just the physical length difference between the two necessitates driveshafts.
Just plan on it being an expense.

 

[RockKrawler]

I had to replace both of mine when swapping in the 205 ,just drive up the street to Driveline Tech and had Brian make new ones. Don't blame him for moving ,but damn it was nice having him so close for all those years.