[somedayaurora]

Originally Posted by olddog

The 428 is a center oiler design. If memory serves the oil goes to the cam first and then down to the mains. The 427 side oiler put oil to the mains first and then up to the cam. As cast from the factory (today people improve the FE oiling) the 428 cannot turn much north of 5500 rpm in a long race without loosing bearings. The 427 side oiler could turn close to 7000 rpm. The racers of those day were turning them 7500 - 8000 rpm but I suspect those were modified.

The 428 smaller bore limits the valve diameter, and has smaller valves than the 427. It cannot breath as well as the 427, as a result. Therefore as cast, the 428 cannot make as much power.

Blykins is correct that Ford advertised 335 Hp for the 428. Shelby advertised 390 hp and noted that he had modified the engine.

I hope this is the information you were looking for.

It is ! Thanks
SDR