Vintage Traction Bars

[BillD]

I picked up a set of old leaf spring traction bars for a first geeneration Camaro. I believe they are the original design lakewood slapper bars. They are made from 2 1/2" square tube and the rear of the bar extends past the rear axle. They also have u-bolts in front of and behind the axle. The two bars appear to be a matched set. However one bar is 2" longer (in front of the axle). Would anyone know the reason for this? Thanks for any help.