You might consider new ones. Check around, I bet you can still get them.
I priced them for my '71 3/4 ton and they were around $70 each.
By the time you pay shipping, have them cut, you will have alot into the used ones.
Just an oppinion.
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63 Impala*66 Chevelle SS*69 Chevelle*69 C10 Stepside*71 Cheyenne 20*72 Chevelle
Parts for sale:
http://www.angelfire.com/trek/mr409/items4sale.html