The Stovebolt Site Forums The Shop Area The Electrical Bay Help me ID this distributor

I am in the process of trying to decode the work of previous owners of this 1946 3600 pickup. The engine casting numbers indicate that the 216 engine is actually from 1949. Somewhere along the line, the electrical system was converted to 12 volt with a reducer for the dash gauges. So far, so good. What's making me crazy right now is trying to figure out what I have for a distributor. There is no label on the outside but the breaker plate indicates that it's a model 1112403, serial 5L15 so that looks like a solid 1955 to me. At least the breaker plate is from '55, not sure about the casting though. Also, in looking at the rotor, it seems much longer than the standard rotor from 1946 or 1949. I measured it to be 1.687" long from contact point to the back of the rotor arm.

Also, I have to replace the vacuum advance, which looks like its a 1949 model in order to fit the engine geometry.

So with this mishmash of parts, how does this affect performance and/or settings? Is the dwell setting any different from year to year? Is the timing curve affected, if so, how? Is there any reason for me to be worried that this setup will be a problem? I'm assuming that my tune-up kit will be points, rotor and cap from '55 and gapped to '55 specs. Do I have that right? Will I have to make any adjustment to the timing other than the standard setting? Oh so many questions I have... Thanks in advance for your sage advice.

Hy electors, your distributor number is of a 1955 second series with 235, so order your tuneup parts for that application. The dwell or point gap and timing should be the same, there may be some changes on how the advance comes into play, but if anything the later distributor should be a refined version of the older model. If the distributor is in good shape and everything is set to specifications your engine should run well, hope that helps.

Thanks 3B! But not sure what you mean by "1955 second series with 235." Does that mean that it was made to go with a 235 even though I believe my engine is a 216? Is there any issue with that? For that matter, I'm only going by the sales info that indicated that it is a 216, I have not actually been able to confirm that it is a 216. Still looking for a definitive way to tell the difference since it is reported that the outsides are the same. The quest continues....

The '46 216 is very different visually to a '55 235.

The 216 has a long side plate that goes all the way up to the valve cover. Valve cover is held by 2 studs in the center.
The 235 has a short side plate , which stops below the head and the valve cover is held by 4 screws.

what are your engine casting numbers ?

Post the s/n stamped on the pad right behind the distributor

Okay, so this is one of those duh moments. I really should not be trying to think too much that late at night....

Of course I have a 216. The casting number prefix is GBA so that means that it is a 216 cubic inch from 1949. I knew that already but suffered from a "senior moment." Now where did I put those car keys? :-)

Thanks

Hy electors, distributors are physically interchangeable between 216, 235, and 261, there are different part numbers for the different engines, those different numbers represent the parts (vacuum advance, advance weights and springs) that the engineers felt would work well with that particular engines specifications. In 1955 we had two different truck designs, the first or "A" series which looks like a 54, and the second or "B" series which looks like a 55 and newer. Your distributor is listed as applicable to all 235 powered trucks in the 55 second or "B" series, hope that helps.

The 216 probably has a steel cam and should use a distributor with a steel gear. The '55 distributor probably has a cast gear designed for a cast cam. I don't know if there is any problem with running a cast gear on a steel cam.

pics

In later years Chevrolet sold the 403 distributor as a replacement for all years, so I figure they felt the cast gear was fine on a steel cam. Never the other way around though.

Thanks, Dave. I was wondering.