Large valved 273

TMM - sorry about the X's.

D/Darts had stock 920 heads - 1.78 and 1.50 valves. They are closed chamber swirl port heads. Mine ran a best of 12.95 at 105 with launch and shifts up around 6900 RPM's. The Doug's headers had 1 3/4" primaries and 3" collectors back then. The guy that raced my first D/Dart used a 36" collector extension when he took it to the strip. I think he referred to it as a "stinger".

In the TSB D66-HP -1 dated April 18,1966, there is a section entitled `Car Operation For Best Performance '. This TSB can be found on the D/Dart website and the Hamtramck site.