Actually, you toss the blocks that are used on the 53 and earlier models and just rest the bed on the cross sills. You will not have to block up the 54 bed. The cross sills (braces) will rest on the small rubber pads with the frame underneath. You will find that your running boards will align with the holes in the bottom of your rear fenders. Take a look at my current vehicle, a 54 and you will see what I mean.

Dan
"I think I can, I think I can"
My Current Truck: http://ILovePortTownsend.com/54Toy.htm
My Last Truck: http://ILovePortTownsend.com/Truck_files/53.htm
My 59 Vette: http://ILovePortTownsend.com/Truck_files/59.htm
My High School Vehicles: http://IlovePortTownsend.com/Truck_files/late50s.htm