I'm going to be pulling my stock 8.2 out to put a 8.5 10 bolt in my 71' GTO,I understand I need to shorten my drive shaft. I figure I'll measure from trans to rear end before I pull the old one,and remeasure with the new rear installed. Instead of cutting the original,I'm looking for a donor. Were there any cars with a shorter drive shaft that would already fit? Any certain models better than others? anything else I need to know?
Thanks
shorten driveshaft swapping from 8.2 to 8.5
Re: shorten driveshaft swapping from 8.2 to 8.5
Well of course any 1971 1972 Buick skylark or Olds cutlass with the same length tranny will work perfectly. BUT if you doing all this work it is best to measure the length driveshaft you need after it is installed. REALLY no way around that. If you try to save time here you could be sorry. find out who you will use to cut and balance the shaft. Then ask them where to measure the length from and to. DO THIS as each shop may require a different point of reference. Then if the shaft was made wrong this will NOT be an issue between the customer and the shaft cutter/balancer. Ok? Jim
J D Race
Re: shorten driveshaft swapping from 8.2 to 8.5
Ahhh,thats so obvious I guess I missed it,use an Olds or buick driveshaft.
I thought of another question.Is there a difference between 4-speed and auto trans. driveshafts,length wise? I've heard there is,but not sure.
I have a 4-speed so it might be a bit harder to track down a Olds/buick 4-speed driveshaft is there is a difference.
I thought of another question.Is there a difference between 4-speed and auto trans. driveshafts,length wise? I've heard there is,but not sure.
I have a 4-speed so it might be a bit harder to track down a Olds/buick 4-speed driveshaft is there is a difference.
Re: shorten driveshaft swapping from 8.2 to 8.5
Yes there very well might be and another difference could be the yoke out put from the trans as it could have a 400 yoke or a 350th out put yoke... 2 totally different application.
The heavy duty 4 speeds had the 400 output shaft and the standard duty had the 350th out put yoke smaller
To be safe you can install the rear and install the yoke you will be using and measure center to center on the saddles and then go to a junk yard or drive line shop and find or have one made to the correct length. Most yards have piles of drive shafts so you should be able to find one the correct length with in a 1/4"
The heavy duty 4 speeds had the 400 output shaft and the standard duty had the 350th out put yoke smaller
To be safe you can install the rear and install the yoke you will be using and measure center to center on the saddles and then go to a junk yard or drive line shop and find or have one made to the correct length. Most yards have piles of drive shafts so you should be able to find one the correct length with in a 1/4"
J D Race