700R4 driveshaft solutions

[skymangs]

I have a 70 longbed fleet. Right now it has a th350 with a two piece shaft. I’d like to convert it to a 700R4. Does anyone know a shaft that would be compatible? Two piece, 1 piece... Any advice on the appreciated. I don’t want to have to cut and balance if I don’t have to.

[Bigdav160]

I've cut and re-welded more driveshafts than I care to count. I never had the need to balance.

YMMV

[Rick Bollinger]

I could be wrong but your driveshaft may bolt right up. The 350 and 700 share the same slip yoke and I believe may even be the same length. My 400 was 2 1/2" shorter than my 700 and a different yoke.

[HIGHWAY BY THE SEA]

When I converted my 68 longbed stepside to a 700R4 I had to have a special drive shaft made at a shop.

[kidatheart]

Originally Posted by HIGHWAY BY THE SEA

When I converted my 68 longbed stepside to a 700R4 I had to have a special drive shaft made at a shop.

Did your 68 have a TH350?

[HIGHWAY BY THE SEA]

Originally Posted by kidatheart

Did your 68 have a TH350?

No.

[skymangs]

Thanks all for the replies. I guess I was looking for a common solution. Like the driveshaft from a park avenue wagon is the perfect length, or something.

[Rick Bollinger]

67-70 trucks came with a 400 trans. I don't believe the th350 came till 71. I may be off on the years but I do know they came much later. Also when you go to set up your 700 consider using bowtie overdrive's TV kit for your carburetor. It's a little more expensive but cheaper than frying a new trans.

[Rick Bollinger]

Here is a link to there website. There is a lot of great info here.

http://www.tvmadeez.com/article/index.php

[Madkidd007]

This is actually quite simple. It depends on which th350 is in it, there is a long and short shaft. But at the end of the day it would have to be shorter if anything and not longer. Have it shortened & balances. Too cheap not to do it and guaranteed a smooth driveline

[Madkidd007]

Thought I’d add this also

[Warship2k15]

Originally Posted by Madkidd007

Thought I’d add this also

Good info.It looks like if you get lucky and have a long shaft turbo 350 that it will not need the driveshaft modified.

[Lancialonnie]

I just had the 350 in my 72 replaced with an early 700R4. The driveshaft needed to be shortened a little bit (either 1 1/2 or 2 1/2 inches, can't remember for sure). I dropped it off at the commercial shop that does lots work on large trucks and they had it ready to go the next day. It sure is nice having overdrive! I have to watch my speed on the freeway now as it is so quiet I don't realize how fast I am going!

[skymangs]

Thanks all. I Feel much more confident about this swap.