Since they were designed for a boat (engine either idle or 80~90 percent throttle); they may not have the circuitry for the engine RPM change on a street engine. Without studying the circuitry, I really don't know. Don't remember ever rebuilding one.

Of more concern might be the generation. These are 20 series, which was superceded by the 23 series, which was superceded by the 28 series, which was superceded by the 228 series.

If they are new old stock and cheap (parts are NOT going to be cheap), why give them a try.

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