In the JS page 4-5 there is a chart, and there was a 13 leaf A-5560F for the 130 A & B Canadian...
Why a 29 ccpu had a 13 leaf is anybody's guess...It had 12 in the front if I remember right.
Here is the thread where I removed the spring and replaced the broken rear cross member.....I'd guess they were hauling something darn heavy to break that cross member...
https://www.fordbarn.com/forum/showthread.php?t=182182