.068 .066 .065 .062 jet size were used on 1973 plastic bowl vent carbs with .062 the most common used on cars and light trucks.

https://quadrajetparts.com/metering-jet ... 2_149.html The jets in this link do not fit pre 1974 air bleed carbs.

This is what the older jet looked like http://www.carburetion.com/Products/Pro ... =C2-BBD-45

That picture is a bbd air bleed carb. That brass tube with holes is main well emulsion tube. Your jets if .062 are best left alone. Carter service bulletin, number 151 May 1972 mentions wet fuel level up or down .015 and float level tolerance .030 up or down. Set to best engine operation. Check wet fuel level.

Corrected info seems 1971 1972 and 1973 used same bowl vent. The 1973 had some features that were different than 71 and 72 ,but not the bowl vent.

71 or 72

1973

Internal bowl vent to top of venturi was different.