I am fine tuning my SBC (383) for fuel economy here are the stats:
Base timing 10 deg with no Vac
All in timing 34 deg @ 3200 with no Vac
Base timing 20 deg with Vac
All in timing 44 deg 3200 with vac
15" vac at idol
13-14" vac at 2200 RPM (65 MPH)
Plugs are dark brown a Little darker than should be but Car runs very nice response is good
I am confused about the vacuum not dropping out guess I don't know all I thought I did!
It seems like I need more open butterfly on the carbs but still a little confused on how to get that with out a lean condition also not sure if I need to re curve the dist to bring the all in RPM down from 3200.
The car is a rod not a racer do more cruising and the occasional burn out but very occasionaly just to prove I can still do it
Any positive thoughts would be appreciated I am out in the hot sun trying to figure it out?