Usually don't enter into these, just read posts and go on since this is my kid's computer, but when I find a good product, I think it needs to be pointed out. We do wheat and milo in NC OK. WE installed this cylinder and concave combo from St. John's in '98, in an l2 (small engine) and installed dealer recommended setup in an l3 (big engine). the machine with the St. John's setup far surpassed the OEM in ground speed, capacity and cleaning. The dealer and St. john's both promised money back guarantee, so in '99we returned the setup to the dealer and installed another St. John's combo in the l3. We've run gleaners C's, G's, and l's for 30 some years and have never had them work this well.