67-72 Pickup weight of long bed vs. short????

[Street Smart]

I`m gonna start another project, looking to do a "drive to the track" vehicle. Something to take on the street car nights. Maybe high 11`s, low 12`s, (no bar). The whole towing the trailer thing gets tiring sometimes, and expensive. Probably gonna be a 67-72 pickup I was curious if anyone knew how much more a long bed pickup truck weighed over a short bed. I`d guess 20" of chassis, 12" of D-shaft and 20" of bed. Any guestimates?
I found a clean long bed, so i can just focus on the drivetrain and not do a full restoration. Curious how much I`m giving up in weight running the long bed over the short.