Ok bringing a dead thread to the top rather than making a new thread as I have a question about the link here,
the page says
Add Width to compensate for drums as follows:

4" - 5" for small cars 5" - 6" for intermediate cars 6" - 8" for large cars

Mine would be this
58" - 59"
'49 Plymouth, '61 Chevrolet Impala
'65 Cadillac, '66 Buick Wildcat
'66-67 Chevrolet Big Car, '72 Charger
'69 Oldsmobile 88, '72 Chrysler
'72-73 Torino


The question is will these fit my car? or do I need to add 5-6" to a rearend that will fit, meaning look for a 52-53" rearend?