Distributor - Which One to Use?

[billrigsby]

I have three distributors, not sure the best route to go,

thats the problem piecing an engine together from different sources.

 

Two have vacuum advance on does not, the one without is by far in the best shape,

one has no ID Tag, anyway to ID it without that?

 

The manual sheds no light, not sure why there is no P/N listed for a B-1-D?

 

 

 

 

 

 

 

Edited November 6, 2020 by billrigsby

[Jerry Roberts]

Looking in my Auto-Lite catalog for truck B1D 1948 ;  The correct distributer is the IAO-4002-1 , without vacuum advance . Some of the larger trucks didn't have vacuum advance . 

[Jim G]

My 1949 Fargo 1 ton with the 9 foot box doesn't have a vacuum advance distributor, 

[greg g]

Loaded trucks are not known for their snappy acceleration, or quick increases from idle to working rpms, so no real need for a quick advance of timing to anticipate a quick squirt into the passing lane.  Looking at the charts in my 46 through 51 service manual notes a small adjustment of both mechanical and vacuum advance curves. Curves got steeper and quicker as gas got better and compression ratios increased.

 

The distributor in my 56 Plymouth 230 is out of a 54 Dodge pickup.  The difference is maybe 3 degrees over the stock 46 setup. I doubt I could feel any actual difference among them.

 

That said, use the one that seems to be the least mechanically worn, with the sharpest breaker cam.

[billrigsby]

10 hours ago, Jerry Roberts said:

Looking in my Auto-Lite catalog for truck B1D 1948 ;  The correct distributer is the IAO-4002-1 , without vacuum advance . Some of the larger trucks didn't have vacuum advance . 

I was thinking that was the original, one has 25'" scribed into the cap, so I knew it was not that one,

one V-A Dist was on the Car engine disassembled 2 months ago, I know (think) I should

have had a fourth but did not find it when I did the inventory earlier this year.

 

 

2 hours ago, Jim G said:

My 1949 Fargo 1 ton with the 9 foot box doesn't have a vacuum advance distributor, 

That will be the one I go with.

 

 

1 hour ago, greg g said:

Loaded trucks are not known for their snappy acceleration, or quick increases from idle to working rpms, so no real need for a quick advance of timing to anticipate a quick squirt into the passing lane.  Looking at the charts in my 46 through 51 service manual notes a small adjustment of both mechanical and vacuum advance curves. Curves got steeper and quicker as gas got better and compression ratios increased.

 

The distributor in my 56 Plymouth 230 is out of a 54 Dodge pickup.  The difference is maybe 3 degrees over the stock 46 setup. I doubt I could feel any actual difference among them.

 

That said, use the one that seems to be the least mechanically worn, with the sharpest breaker cam.

The IAO-4002-1 with out V-A is by far in the best shape.

 

 

Thanks to all.

[Dodgeb4ya]

I ran a 265 truck built engine with out vacuum advance distributor for awhile years ago.

Later I tried a vacuum advance car distributor.

It had a little better performance and better mileage....it' still in it 35 years later running strong.

 

[billrigsby]

 

Also looking into the Pertonix Ignition Conversion, 

I have seen bits on here about them, seem to most all be positive?

Should increase reliability and avoid that aspect of tune-ups.

 

Any comments?

[greg g]

I've known several who's pertronix units crapped out on them stranding them in dangerous situations.  If you decide to go that way, carry one of your others set up and in the truck.  If the pertronix takes a dump, you just swap out and be on your way in ten minutes or less.

[Dodgeb4ya]

None of the trucks from 1 ton up used a vacuum advance.

No worry of the diaphram failing.

[desoto1939]

accoding to my autolite catalog the IAO-4002-1 or the IAO-4201-1 can be used  and they both used the vacum chamber VC-3147.

 

Rich HArtung

desoto1939@aol.com

[wallytoo]

i've got about 11 years of service from the non-vacuum distributor that was original to my 1.5-ton '48.  it's now installed in the replacement 251 that resides in the truck.  points are the same ones that were installed when i bought the truck in 2007.

[MBF]

I just replaced the points and condenser in the dist of my 49 1 ton.  Not because of reliability, but because they haven’t been touched in the 25 years I’ve had the truck running.  I adjust them every 5 yrs whether they need it or not.  Going to do the same thing in the 2.5 ton.  I just replaced the distributor from a parts truck that has been sitting for 20 yrs in a field.  Cleaned up the point, lubed and adjusted them and fired it up.  I like the stuff you can see where the problem is, but I’m old.