Well, this is what my book says. "L" means it's a '53. "A" means it's a 216.5 CID. "O" is not listed as an option. If it's a "G" that means it was built in the Flint plant. The numbers are unit numbers. It says it had 92H.P. and 6.6:1 comp. ratio and a 1 BC carb set up. Hope this helps,
Scott


Scott Ward

2 1948 1.5-ton Loadmasters
The red one and The snow pusher
1 1950 3100
1 1955.1 Chevy 6500
1 1954 Chevy 6500 2-Ton
1 1955 1st Series COE 5700
1 1963 K20 (454)
1 1964 C10 (350)
1 1951 1.5-ton Dump Truck
1953 and a 1956 Ford F800

Raising a teenager is like trying to nail Jello to a tree!