Technical No mechanical timing advance

For what ever reason in every ignition I’ve ever messed with I used the lightest springs I could get, like you said all in by 2200. A few I ran the limiting bushing but not all engines liked it, it was for more advance.
I too used venturi vacuum. When I tried manifold I could never get a good low idle. Under controlled driving the lighter springs gave at least 1 more mpg.

 

The other distributor I just did has mid-weight springs and works great. This one now has the lightest springs and works great. Lesson learned that each one is different. I don't know what the original springs in it were for, but on an engine that only spins 5,000 at the most ever, no mechanical advance at 3,000 seemed excessive.

Mine under manifold just didn't sound happy. More laboured.

I'm curious to see how the changes I made impact fuel mileage. It certainly can't make it worse. The controlled driving part of that is what's the problem, though.

 

Just an observation, if you keep putting down 150' black marks, the fuel mileage isn't likely to be any better then it was.
More fun, but not the greatest mpg.

 

It's called tuning

 

Dragy ,
cool testing tool & reasonable priced

 

Miles per gallon may be important, but smiles per gallon is importanter.

 

My father in law has one I might borrow. Although... The seat of the pants dyno is about all I need.

In my opinion for hot rods fast is a feeling, not a number. If you compare your numbers of your old hunk of metal to any modern car you'll be disappointed.