Reasonselz,
Welcome to the Stovebolt
Base on the chassis serial number you have an "early" 1930 131", 1-1/2 ton Chevrolet truck. The "late" 1930's were 157" wheel base trucks with Single or Dual wheels.
The transmission cover 590366 was both the casting number and Parts Book number and was used from 1929 thru 1931.
Your Chassis number is stamped at the bottom edge of the upper aluminum tag on the firewall. From what I can read it looks like 3LRxx16968.
3 = St Louis Plant
LR = 1930 (early), LS = 1030 (late)
xx = month
16968 = unit number
Your engine serial can also help, it's located on the flat machined surface at the fuel pump on the passenger side. Looks like I can read xx9x782. The number should be between 1365366 and 2100284.
Hope this helps,
Mike B
