Doc - no offense, but your post is too general.

There are a number of different power piston springs of different tensions used in the various carbs. The springs come in the better rebuilding kits.

But the only way to get the correct kit WITH the correct spring is by tag number.

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