Guys, i have bougth a carter thermoquad 6-2472 and i'd like to know what engine this will fit?
cfm rating?
What is the better themoquad for a 400ci big block street/strip?
Thank's in advance.

That's not the right part number, you're looking for a 4-digit part number starting with a 6 or a 9, sometimes with a letter at the end, for example something like 94545s or 63423. It'll be stamped on the rear driver's side carb mounting flange where the bolt goes through the carb to the intake, the stamping will be facing the windshield of the car.

Also check out the thermoquad guide:

http://www.carburetor.ca/Tech/Carter/tqguide-Vaanth.html

Thank's, it's a friend question... I'll call him and get the rigth numbers!