The Stovebolt Site Forums The Shop Area General Truck Talk driveshaft help please

I have installed a 12 bolt posi from a 73 Buick Gransport in my 57 3100. I have the driveshaft from the Buick and I have the driveshaft from my 57. Is it better to use the driveshaft from the 57 which is already matched to the GM truck tranny or do I use the driveshaft from the buick which is mated to the rearend? either way it looks like I have to have something cut and welded somewhere in the process. This is the first time I have ever swapped out a rearend and I dont know what to do.

You may be better off having a new drive shaft made to the proper length, rather than trying to adapt either shaft that you have. That way the yokes and u-joints can be matched to the trans and rearend you are running. It will also be properly balanced. Driveshafts usually aren't very expensive, the average here is about $100. Try asking local racers where they get their shafts from to find a good driveshaft shop.

I agree with LONGBOX55, and also would think the length would need to be carefully measured.

The drive shaft shop can give directions on how to measure for a new shaft.

I went with Denny's Driveshafts when I had one made for my Monte Carlo SS:
http://www.dennysdriveshaft.com/

They'll give you specific instructions for measuring your truck so that you get the correct length.

Their prices aren't real cheap, but if you get their heavy-duty driveshaft, they'll replace it if you ever twist or break it. Seems like a pretty good guarantee to me. Of course if you're putting down enough power to twist it, I dunno that you'd want to put an identical one back in.....

What you are looking for is a drive shaft that is the right length and has the right u-joints. If either one is the right length you can get hybrid u-joints put in to use the tranny yoke and match up with the differential yoke when you get it balanced at the U-joint shop.

If neither is the right length you can find one at the junk yard that is. and then get the yoke from your tranny put on and a u-joint that matches the rear yoke.

That's what I did and it cost me about 100 with new u-joints and balancing a drive shaft I brought with me. While I was at the shop I found out that it would have cost me about the same to have them make one for me.

So, I'd call a driveshaft shop. Better still, call your regular mechanic and have him reccomend one to go to. The one the mechanics and dealers use is gonna be the best around for the right price.