I'm thinking about changing from my Longflo filters back to the original air cleaner, for two reasons. One, I want to go back to the original look, and two, I have heard that the carbs actually perform better with the original air cleaner. The air cleaner is from the original flat top carbs, and the new carbs are ZTherapy 3-screws. The flat tops have a square opening, while the round tops have a round opening.

Will the air clearer work properly with the round tops, or do I need a 70 - 72 air cleaner?

Also, would there be any benefit to using a "cold air" induction kit with the round tops, or is that really only effective with FI cars? I'm thinking about fabricating a custom set-up with a scoop below the front valance to feed the carbs cold air. Any thoughts?

Z therapy sells adapters to use your flattop air cleaner on the round top carbs, but I dont think the performance is as good since the air horns are squared. You can normally find a 240Z air cleaner on ebay for less than the adapters, thats what I did, or you could just put some airhorns inside of the filters you have now.

If part of the reason is for the performance benefits of the air horns, I agree that the best option would be to get a '70-72 airbox rather than use adapters in your '73 unit. Any '70-72 airbox should work fine.

Don't know if there's any benefit to a cold air snorkle on this set up.