[t korinek]

speesh harness is different for the 57, I'm sure the 57 truck harness is similar to the burb, probably would be different in the length of the tail lights harness & connectors & dome lamp harness.

I don't have the 57 harness in stock, I can get it, it is still specific to the truck $250

Another option would be to get a classic update kit that would upgrade you to the newer style blade fuse box & allows extra wiring to run auxiliary options .

Thanks,
Tom