Bryson

428 cobra jet is a very rare engine put in gt500 mustangs and the 67 galaxie 500, im 99% percent sure its not a cobra jet

bales74f1

Someone could of put one in a truck or could of built one, but I would say your right. I bet someone put a regular 428 in it but they are still good motors

F250_

If its just a regular 428 any ideas on what cj could stand for?

Aggie*86

"CJ" would indeed stand for Cobra Jet. The 428 was never in a 1970's pickup as standard equipment. In many cases, people bored and stroked ( crankshaft with longer throw) their original equipment 390's and made them into 406's or 428's. There is nothing wrong with that but that is a completley different motor than the 400 M. As for it being a Cobra Jet, highly, highly doubtful. A 390 modfied to a regular 428 (non Cobra Jet) is possible but you wodnt be able to tell the difference from an external view.

That said, a 390 is a rock solid motor. It came in a 4 barrel performance version in Ford Galexies and Mustangs. The truck version can be warmed up with a new aluminum 4 barrel intake and carb. Very easy to do. Would not shy away from the 390 for your use.

Johnboy429bbf

Maybe its a typo.. maybe instead of cj they meant ci. But I also havent personally came across any trucks with the 428 factory.. so I would say it wss a swap