Well I decided to check the valve lash today on a cold soaked engine and expecting to find lots of clearance I found mostly the opposite. Intake varies from 2 to 12 thou and exhaust 7 to 18. Don't know the history of the truck really. Just rebuilt the carb because it wouldn't start or accelerate well and found it was recently gone through and not done correctly. Are the valve seats getting worn, or did someone possibly not know what they were doing? Thanks in advance.

1953 Canadian GMC 9314 w/ (factory) Chevy 235