Patrick:
You need 3 cross sills for your short wide bed and one reinforcing strip.
It is kind of obscure, but if you roll your cursor over the "bed diagram" that first appears on our parts and prices link, you will see it indicates how many cross sills and reinforcing strips are required for your truck.
Also, by the way, if you order your parts from Mar-K, we will include a complete bed assembly instruction set for your specific truck. It answers many of the questions you have about putting the bed back together, including photos and measurements.
Mar-Ktech
