Holley 390 4bbl on my slant 6?

I have been running this system for about 3 years and when I removed the 1 barrel intake and the very small (1 5/8 down pipe) and exhaust manifolds Points system and plugs I went
from 18 mpg to well over 22 mpg running my 390 Holley DP carb...... and yes it is a standard shift three on the tree and moves quite well (allot faster and cooler running engine) and I am still making more changes
I have yet to get to. Trouble free and it will get out of it's own way now

The plug change made a big difference so I would go to these spark plugs

On the hill doing it one step at a time in Arkansas not as fast as the other folks in this thread but still pulls of a 11.27 1/8 mile useing a 170/6... I still have allot to do :coffee2: Enjoy and keep us updated :cheers: