Ok....I have looked and scraped and cleaned and still cannot find any identifying marks on the carbs of my stock, original 73 240. Can anyone tell me how to make the identification? Want to buy rebuild kits so I can get it started.

In US there are 4 different stock carbs for Z's from 240 '70 - 260 '74.

First, are the dome tops round or flat??? If they are flat then you have the '73 240 - '74 260 stock carbs. These are typically changed to any of the earlier type because of the difficulty of tune and finding parts. However, some people have used them on stock motors with success.

Second, if they are round dome tops then check the number of mounting screws holding the domes on the carb body. If there are three screws then you have '72 240Z carbs. Like the later carbs they have water passeges on the bottom so that water running through the intake manifold also goes through the bottom of the carb body.

If they have 4 screws then you have '70 - '71 240Z carbs. These are very similar to the '72 carbs except without the water passage in the carb body. Lastly, early '70 240Z carbs, which are 4 screw carbs but only difference is they do not have drain plugs in the bottom front of the float bowl.

Hope it helps!

Oh yeah, for pictures and more description go to www.ztherapy.com. This is the site of a company that rebuilds Z and non-Z SU type carbs.

Have fun!