Note the stats are in distributor degrees and rpm, which are at 1/2 of the degrees and rpm measured at the crank....

Vacuum advance if stock will be:

0.5 to 2.5 degrees at 7" vacuum
7-10 degrees at 11.5" vacuum

Mechanical Advance:

1-4.5 degrees at 600 rpm
6.5-8.5 degrees at 800 rpm
9.5-11.5 degrees at 2300 rpm

Standard distributor for 225- 1 barrel Federal cars... Standard distributor for manual and automatic cars in Canada...

Assuming this distributor is stock (which I'd sure think so because the car is as unmolested as it gets), what would be the best way to recurve it for mileage and power? Or is it fine the way it is?

Until you do some other mods it will be fine as is for now....you could work up to the 8 BTDC initial...to see if that improves your mileage a smidge.

I would highly think about the 3.23's for better acceleration...

Do you know what Jet is installed in your Holley carb (maybe spotted it during the rebuild/regasket?)

The car came with a 621 in it which I'm told is just a 62 close range jet. The car would stall if you even tapped the gas. Tried a 64, but felt so lean at WOT and cruise RPMs that it would fall on its face if you had to downshift to go up a hill. Currently its got a 66 jet in it.

Damn just saw a 3.23 gear set at a swap meet a week ago and the guy said to make an offer.

Here is a two part series in MoparMax.com about ignition timing of two different stock slant six engines in a pair of Darts. All of the mods are ignition related, and the one barrel carburetors remain stock with stock jetting. Just some ideas to add to all the knowledge that has been given to you by the contributors on this forum.

Timing is Everything Tuning for Power and Economy Part I
http://www.moparmax.com/tech/2015/x_11- ... ing-1.html

Timing is Everything Tuning for Power and Economy Part II
http://moparmax.com/tech/2015/x_12-timi ... t-2-1.html

#61-#62 would be fine for a 1945... #66 is pretty rich, I would be looking for a vacuum leak, I also would make sure the carb linkage is properly adjusted and placed in the right holes...

If it stalls off the line I'd be looking to make sure the pump shot is a nice strong shot....

I've hosed down everything on and around the car looking for a vacuum leak on this thing with cars spray and haven't found anything. Sprayed the intake looking for leaks and didn't find anything either.

I have fought with that accelerator pump forever. The stream sputters at the very initial point but is Finland healthy the rest of the way too. I have tried 2 different pumps from 2 different kits, tried shimming it, and changing the rod position for the pump shot on the card and it always has that slight sputter. It's good enough now that it doesn't kill that car when you step on the gas (it used to be a big coughing sputter all the way thru when I got it). I'm at a loss for that one. I don't know what to do with it. But I agree, a 66 jet sounds too lean if 62 really is adequate.

On Holley's the higher the number the more fuel it will flow... the #66 will flow more fuel than the #62.... this can also have an affect on your mileage.

That's why I'm saying perhaps the 66 is too rich if the car is supposed to run fine with the 62 as you suggested

What I can't figure out with the accelerator pump is why it's stream starts so weakly. It sputters for a fraction of the travel and then delivers a smooth steady stream after that. The rubber diaphragm isn't rolled over on itself or torn (though I have had 2 already tear just by driving the car and not taking the car apart and straining it), the fuel passage for the pump shot is clear and it doesn't feel to bind or stick anywhere when working the linkage by hand. Jet wise, I'll see how the 66 feels while cruising on the highway and maybe step it down to the smaller sizes if possible.

Could there be some air getting trapped in the accelerator pump somehow?

How about: Does float level and level of gas in the carb effect the accelerator pump operation?

Which Holley carburetor again do you have?


Holley carburetors can a bit of a mystery until one has read and played around with them for a bit. Wrong jet, idle mixture, and amount of transition slot exposed can cause all kinds of drivability problems along with a mal adjusted accelerator pump.

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67' Dart GT Convertible; the old Chrysler Corp.
82' LeBaron Convertible; the new Chrysler Corp
07' 300 C AWD; Now by Fiat, the old new Chrysler LLC

I've got the good old 1945 Holley. 66 main jet. Accelerator pump set to slot 3 on the adjuster. Float level set to 3/64". According to all manuals it should be flush, but when I set it that way it would flood at idle even with a new needle and seat.

Rebuilt this carb so many times ots ridiculous. Tried Walker, hygrade, gp sorenson and a generic carb kits. Matched every gasket, blew out every passage on the carb, shimmed the accelerator pump, wire brushed all linkages to insure free motion, new base gasket, the list goes on.

Idles great at 750rpms with 18" of vacuum. 7* initial timing. Plugs look good with a light tan reading. Wires all secure as well. Tested for timing chain slack and found almost none. Adjusted vacuum advance pod with a 3/32" Allen wrench 1/8 turn in (far as in it would go) to increase responsiveness of the advance. Now gassed up with 87 octane gas. Doesn't bog as bad off the line, but you can feel it huff and then catch itself if you put the pedal halfway down.

Er…I don't agree that the adjustment you made "increased the responsiveness" of the vacuum advance.

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一期一会
Too many people who were born on third base actually believe they've hit a triple.

I thought I remembered that from working on a couple Fords I had at one point. Turn the screw clockwise to increase vacuum sensitivity. It really didn't turn much at all.