Machining pre 1963 bus rear drums to fit 1968 and later type-1 rear brakes.
When lowering the rear of a pre 1967 bus it is standard practice to convert over to a beetle transmission.
This means either using a pre 1969 swing axle bug transmission or post 1968 IRS transmission and trailing arms, both of the for mentioned transmissions use the same diameter brakes as a pre 1963 bus.
In short “with a couple of modifications” a pair of 1963 and earlier bus rear drums will bolt up to a post 1968 bug rear end.
This is how to do that.
#1 = Remove 17 mm from the snout ' see photo #1'.
#2 = Remove the inner fin closest to the backing plate and furthest from the lug surface 'see photo #2'.
When machining the back fin off you will want to square up into the second fin 1.5 mm.
Then shorten the depth of the drum by machining the rim by 2 mm.
FYI --- THIS PHOTO SHOULD HELP
Post 1968 Bug rear drums have a 63.5mm / 2.5 inch long female spline.
Pre 1963 Bus rear drums have a 90.50mm / 3 5/8 inch long female spline.
