Floorboard date code?
 

I'm in the process of putting my 70 GMC back together. The other night while under the truck I notice what appears to be a date code stamped into passenger side floorboard. It on the outside of the floorboard directly behind where the wheel well is located. The wheel wells are currently out. If they where in I wouldn't be able to see it.

The date appears to be 19 3 1970

Has anyone seen this before?

Thanks

Re: Floorboard date code?
 

My 70 Chevy had numbers stamped into the same location on the floorboard. I thought they were part numbers for the individual pieces of sheet metal that make up the floorboard. I will have to look again now.

Re: Floorboard date code?
 

My 71 K1500 has a date stamped in that location.

Re: Floorboard date code?
 

My 70 GMC had this in the bed towards front cab.