In 1964 I saw one of those at the drag races. It ran like it had a 427 so a few of us went to check it out. He was running a built 289 in the low twelves! Of course we were quite curious how he ran so hard. He said, "You rev it to seven thousand at the line and dump the clutch. When the tach hits nine grand you shift."
A well built hi-po 289 is no joke.
Those 260/289 Fords were a real suprise as stock units. The factory built HP289's really did not require tach's........just shift when the ears itched. The advertised 271 hp was somewhat under rated. Very strong engine! I've had several.
The things that come to those that wait may be the things left by those who got there first.
