What are the carburetor identification numbers stamped on the edges of the mounting flanges?

Some carbs have the airvalve, some do not.

Generally, both engines would have identical carbs.

Jon.

Good carburetion is fuelish hot air
The most expensive carburetor is the wrong one you attempt to modify.
If you truly believe "one size fits all," try walking a mile in your spouse's shoes!
The Carburetor Shop