In my early 1972 400 I used a 292-509 purpleshaft, and it was a real good runner.
It had the std. bottom and std. 906 heads with a Holley street dominator and a early Thermoquad.

It was one of my best street engines ever.

1970 Super Stock Challenger ex. Paul Rossi
1968 Dodge Dart GT 340
1968 Dodge Charger /6 3 speed manual
1966 Chrysler 300 Loaded
1968 Dodge Charger R/T 440

1968 Mini Cooper