they should run 14 or so, i seen one this weekend running 12.3 4-speed car not stock, i love the cj cars wish i had one, mine is a 351w car now 408, but always liked the big blocks.
They were rated at 335 hp from the factory , but the actual power was closer to 400 . The std 428 pass car motor was rated at 345 hp....... so it's obvious the CJ rating was fudged........
i believe Mustang Monthly dynoed one on a modern (SAE net) dyno and got 274rwhp from it. This means 320 hp at the flywheel is probably what you're looking at. Torqe was up in the mid 300s I believe, too. All of this might sound somewhat disappointing given its original rating, but in all honestly, its actually very impressive. One of the fastest cars of its day. With all that torque, it will certainly shove you back in the seat with authority.
In SAE gross terms, yes, 400 was more accurate. But theres a reason they got rid of SAE gross lol.
Stock its about 412 HP and 444 FT lbs torque. Runs a 13.6-13.8 quarter mile. With some less restrictive headers and exhaust you can make those big ports breathe and get some free... sort of... HP.
Kevin
i really, really don't think you're going to get 412 HP out of a stock 428 unless you're counting in SAE gross... and we really, really, shouldn't use that, its very deceptive
As an Ex-Owner, and having run the car many times for magazines, I can answer you pretty good. Bone Stock with bad tires, good luck in hooking it up. Good tires, low 14's. My SCj with 3.91's, headers, 750 carb, and electronic ignition with BFG radials ran 13.8's for two magazines. Hardest problem was launching the car! Had to "granny" it off the line, then stood on it! Through the traps at the top of third gear, Motor screaming, what a ride!!!!
Watch Hemmings Mustang Mag for an upcomming article about my open-track adventures with the car.
Now it sits in Las Vegas, in my X's garage, collecting dust......
if you take it to the dyno, the same one they measure modern cars on, it will not read 410 hp. A Corvette z06 has 400 hp, and it will read so on a dyno. The 428 will not. (for reference, the z06 would probably be at around 475-500 hp stock if measured on an SAE gross dyno... i just try to make sure everyone compares cars on an even measure, and a lot of people don't understand that a 300 hp car in 1969 isn't the same thing as a 300 hp car now... its a pet peeve i guess)
The 428 is extremely torquey, and if you can hook it up that is a big advantage over comparably powered cars.