Use flexible suction hose instead of the PVC pipe. For the few dollars this mod will cost its well worth trying it first before spending $20_ft on a commercially available set of rock guards. Alot of guys have the suction line sitting around in their shops and the clamps are cheap,I've heard of guys spending as little as $10 to do a 25ft head, now where are ya gonna prove a machanic wrong for as little as $10IJ lOl Give it a try, the mod takes less then an hour and pays for itself with the first round of the combine in the field,cant beat that .