Paynes Forks 1200-Lb. Capacity Fork Stabilizer Bar for Item# 103606 | Bucket Accessories | Northern Tool + EquipmentThis is basically the same concept I am using.
Paynes Forks Light-Duty Forks 1200-Lb. Capacity, John Deere Green, Model# PFG1200 | Bucket Accessories | Northern Tool + Equipment
David
Attachment is a photo of the above link... Did you see the stabilizer bar on that page? That might give some strength, at least between those two points. Welding a plate would help, too.