The Stovebolt Site Forums The Parking Lot Big Bolts 1960 GMC V4000 help

To answer your original question. The brake specification is on the inside of glove box door on the "Service Parts Identification Plate". Lots of good info on that plate. V 4000 should be Chassis Cab 14,500 GVW. As you know the N is 60-61 and the P is Pontiac, MI.

I have a 1960 1/2T and several 1960 GMC specific books including Master Parts Book, if you need any more info.