I just bought a 73 f250 off a guy and it has a 429 in it. Inside the engine compartment it says 429-4v. How can I tell if it is a thunder jet or a Cobra jet? If anybody could tell me that would be great thank you.

 

these never came stock with 429s and if there a tag on the air cleaner or valve covers that could have being installed for looks try to find some numbers on the block,intake,heads ect that would tell you for sure as a lot of 429/460 parts interchange and its easy to make a 429 clone the nunbers on the heads will be the numbers to look for