sixty8 xl

Hi can anyone shed some light on these head #s The c6ae-u are on my 428
are the c6ae-r a better performance head? any info would be good as I am new to fe's THANKS!

kdtrucker

The C6-U heads that are on your 428 are a good head but with small intake ports. Similar to the C8-H or D2-AA the small ports are velocity ports. The C6-R heads Have the tall ports and is made for more airflow. Although the heads, if stock will more than likely have the same valve size, are both good heads I would go with the C6-R for more air.

sixty8 xl

Thanks for the info. I have found a set of old hooker headers for a 68 galaxie that I will get coated and put on with the c6ae-r heads do you think it would be worth putting in the larger valves without doing anything to the engine as it only has 5000 miles on it? I was told the c6aeu heads (14 bolt )were 390gt heads. do you know what these would have come on Thanks

kdtrucker

The U heads are 390 heads possibly GT. Good heads, but not if your going for "big" performance. They have the smaller intake ports made for velocity...flowing alot of air through a small port, where low end torque is achieved.
The R heads are a (352) or 390 and 390GT even possibly 428, tall ports for more air flow. Install a set of CJ (2.09/1.65)valves in the R heads and you'll have a nice set.
The 14 bolt patern was designed for the type of exhaust manifold bolt configuration used.

sixty8 xl

Thanks again for your response much appreciated Thanks

FFR428

Before you go to the trouble of getting the headers coated be sure they line up ok with the R heads exhaust ports. The C6-U heads are GT heads but also have the exhaust ports raised a good .250+. If the headers you have are for the later raised port heads there might be a port mismatch with the C6-R heads. I have the Hooker 6114's for the Stangs and Cougars and they don't match up well with the GT head ex ports. No biggie as they will be fitting to the 427 tunnelport heads to which they are a good match. If your headers are for the 68 Galaxie they might be for the later style heads. Just a heads up on that. Good luck.

sixty8 xl

Thanks for the heads up my engine is a 66 428 but i'll be sure to check the match. I am going to put in a cam as well but thats all (the engine has 5000 miles on it) Any idea of what lift/duration would be good for lots of torque as you Know its a big car.

FFR428

Well that's the thing. 66 was the transition year from lowriser to GT style (lets call them) with the new velocity port design. So depending on what state the car was sent to it could have either type of heads. By 67 the only lowriser heads left were the marine C7JE heads. And the 68.5 CJ's after that. I'd imagine you could get service replacements of the earlier C4-G heads but don't know that as a fact.