Re: 78-79 bronco milage
yeah, I keep a pretty low profile on the highway runs, a lot of small towns and two-lanes to and from the beach.
I ran the vac advance and played with timing until I was blue in the face trying to eliminate low-load spark knock for a long time after installing the intake/carb/headers. Tried retarded combos back to almost 0-deg adv, and it would barely start, advanced beyond 10 deg, port and manifold vacuum....every combo I could think of, and finally found by accident, after resetting the timing back to stock 10deg BTDC, and taking it for a test drive, and not realizing that I had left the vac hose off and plugged with a golf tee....that it ran better than every combo I had tried. Plugs are Bosch gapped to stock 044 - I had run manifold vacuum up to 44 deg total advance with 050 gap as one of the combos (38 deg total adv is recommended max for this motor), and it ran like crap. Bottom line, with the intake/carb setup listed, 10deg adv, 044 gap, stock ignition/coil, Bosch Platinums and an open air cleaner (no smog), it has been "set-it-and-forget-it" for four years with regular tuneups, great off the line, good midrange acceleration, no spark knock under light or heavy load. Don't ask me why - I'm no motor expert, just lucky I guess.