Hey guys - looking for a little insight as to the distributor in my '73. It is a working/functioning tach drive dist. (not TI). It's working fine but I'm considering a rebuild during the winter mos. and I want to make sure it's done right. 

My dilemma is that the stamped ID tag is gone. Knowing most of the car's history and the fact that is has 67xxx miles, it is believable that one of two things may have happened. Knowing how these cars chew up tach gears, it is possible that this is a generic rebuilt unit that was installed sometime in the past and the original/tagged unit was sent in for a core. The other is that this is the original, serviced for some similar reason and the tag went by-bye. I tend to believe scenario #1.

I know I can purchase a new dist. tag with all the right numbers, but what I really want to make sure of first is that this is (or is not) the right dist.

All the searches I have done point towards no identification beyond the tag, no casting dates, no P/N stamp or anything that would properly identify the dist. If anyone knows something different, please let me know.

The next issue is the proper dist. for the car. According to my research the L48 cars used a 1112098 dist. and the L82 used a 1112130. So what is the difference between the two ?? And how do I identify what's in the car ?? I suspect the difference has to do with how the advance curve is set up and perhaps a different vacuum advance. That should be all part of a professional rebuild, shouldn't it ??

Happy New Year and thanks in advance for an insight or information you can provide.    

|UPDATED|1/23/2015 2:55:19 PM (AZT)|/UPDATED|

My '74 has a little over 50 thou on the original, factory tagged distributor. Never been rebuilt, never had anything done other than points/condenser changes. The flimsy aluminuminum tags usually get damaged by heavy-handed timing practices, so your tag missing doesn't necessarily mean it has been rebuilt, or swapped. I believe your distributor body should be cast iron. If it is aluminuminum, then it has been changed. Other than the tag, there are no identifying clues as to origin. One way to tell if a dist is an original is to look for a chisel mark on the base, right where it fits into the intake manifold. At the factory, once the timing was set, they used a chisel to mark both the dist housing and the intake to have a reference point for future troubleshooting at the dealer level...to see if the dist had moved either during shipping, or by virtue of the hold-down clamp being loose.



(ignor the part numbers on this dist...it is not a Corvette dist.)


The difference in the 2098 dist and the 2130 is as you suspect...different advance curves, done by using different weights/springs. Afaik, the vacuum advances were the same on all of the small block cars of that era.

Thanks Adam, that's exactly what I was looking for. I'll start with the chisel mark tomorrow. Any recommendations on who could provide a quality dist. rebuild to the 2130 specs ??

|UPDATED|1/5/2015 10:26:16 PM (AZT)|/UPDATED|

Finding someone with the know how, and equipment to properly set up a point type dist these days is getting harder and harder to do. My only suggestion would be to ask around the local (old)car club guys.
It doesn't really take much to rebuild one, with new bushings/weights/springs....anyone can do that. It's getting it set up for YOUR application correctly that is the problem. Granted, a stock, off the shelf dist will prolly work just fine in most cases, but....for it to be really right, and get the most out of the engine, it should be dialed in on a machine, by a competent old-timer.

As a side note, the bushings in these things are never "one-size-fits-all". A lot of the aftermarket bushings are just a little too large(O/D), and folks are splitting their dist housings left & right trying to get an incorrect, oversized bushing to fit. Best thing is to remove the old bushings, and mic the I/D of the housing, and get bushings to fit that measurement. Most places that sell the bushings have several sizes available, for just that reason.

Hey Adam - I dug under the hood of my "73 this afternoon to check out my dist. Good news, good news and I could use your opinion.

Good news is the my dist. housing is definitely cast iron and I found a chisel mark on both the housing and the intake manifold just below the tach cable outlet. Pretty tight quarters to make a chisel mark, but it's there.

So now the opinion, both marks are there and line up "relatively". The are about 1/8" away from each other in rotation. Lining them up would cause me to retard the timing.

Do you think these are good indications of the original dist. and is the gap believable compared to the original factory settings ?? I'll double check my timing, but I think I'm pretty close to the 8d BTDC spec. Possible wear/slop in the timing chain and gears ??

Thanks also for the bushing info., I'll use that as another point of reference when looking for someone to do the rebuild.   

I'd say you have the original dist in there.
 The marks were made before the engine was installed....no ignition shielding, etc in the way.  The marks are really more of a point of reference than a "gotta be right here" type thing. Don't think I've ever seen one that hasn't been moved, except a brand new one that has never been thru a decent tune-up. Timing chain/gear wear can account for it being off the mark, as well as just being timed for better performance.
Depending on any wear, you should be able to bring your original dist back to good working order fairly easily. If the shaft fits nice and snug in the housing with no, or very little side/side play, the bushings are prolly ok, and don't need replacing.

Thanks Joel, sorry for calling you Adam. Never noticed your real name at the bottom !! So your response made my day and I'm going to do some research for a local source to inspect and rebuild my dist. if necessary. Once it's all good, I'll have no problem ordering a replacement ID tag for it.