Originally Posted by gearjammer38
so ive got to cut the end of the axles off?
No, it isn't necessary. I didn't think about that fact as I am always using mine to either narrow the housing, or removing the stock axle bearing ends and replacing them with the common Big Bearing Ford 9" end.
The BBF housing end is the most popular for racing, gives you a big bearing pressed on the axle eliminating the need for C-clip eliminators on c-clip axle retention rear ends like 10 and 12-bolt GM and 8.8" Ford, and has the most options for disc brake conversions.
If you are just using it for checking a housing during and after welding you just need pucks for the carrier bearings and to fit in place in the stock axle bearing ends. Put the bar through the two installed carrier bearing pucks and then use the axle bearing pucks to confirm the alignment of the ends by sliding them over the bar to meet up with the factory housing bearing ends.
My alignment bar is about 6' long, so I can make nearly any width rear axle needed for hotrod cars and trucks.