Just my :2cents: regarding a rear blade for your tractor. I would get nothing less than the LP2684
I think a L3940 could make junk of that blade especially in the 7' version. There are no braces running across the moldboard. Once you put it in tilt it would really work on it. That blade does not look much better than a RB Woods and bent and cracked a weld on one of those with a Ford 8N.