my 73 duster was a 6 before being switched to a 360 ,,8 3/4 rear,, 742 case in rear,, have my 340 block in shop now for 416,, and that shaft just looks punee,,thanks for info,going with scat internal balance kit
Most factory shafts were intended for normal street use so their not all that beefy. Dr. Diff has a pretty good deal on a 3" Strange Engineering shaft for $330 plus shipping if you want to upgrade. Here's a link to the page