Frame connectors

I was looking through a magazine and noticed all the frame connectors don't cover the early A's, why? as long as the wheelbase is the same isn't the stub rails in the rear the same as the later A bodies? the rear rails on my '64 are 2 1/2" wide and from the crossmember to the start of the rear rail is about 43". anyone have a set for the 111"ers or could check there car? Thanks.