Quote: ... The 292 and 284 are lucky to get 8-10mpg on a good day.
I've gotten 13.5-14.1 on the highway, at 70mph (with a spirited sprint or two even). 3.54 Dana, 440 4spd, .484 cam in a 71 Charger R/T. Also pulls right aroun 9-10" of vacuum at idle. May actually be a bit better than that now, as the last dyno run, we advanced the timing a few degrees.
As mentioned, throw as much timing at it as it will take. My initial is currently at 18º, which puts my total right around 39-40º.
