Acreage owner here, so you pro's might not be interested, but then again you might, as I mow alot of grass. I run double blades off and on on my M72, and my 3260 (Antique IH deck on a small farm tractor.) but not on our JD 430. Today while I was changing blades on the M72, I accidently picked up a blade for the 3260, the blades look about the same except for they are shorter, and I got to wondering if you could run a shorter blade or the same length blade over the spacer, to improve vacume, and give a high second chop effect. I didn't mount them that way, but was wondering if someone else might have thought of that, or tried it. I think it would help, but don't know. Also has anyone ever used a shorter blade as thier doubled blade? We mow about 25 acres of ground that used to be pasture weekly, so I just about every week have to change the blades, and I alternate between doubles and singles due to the time it takes to sharpen them and the time I have. Thanks in advance for any assistance you give.