Some time ago we discussed a problem with rebuilt YBlock distributors.  Cardone, the source of these rebuilds was using rebuilt small block Ford distributors and selling them as 1957 and up YBlock replacements.  The issue was the position of the drive gear in the small block distributor.  The distance from the mounting face at the base of the small block distributor body to the gear was not long enough causing the distributor gear to miss the load bearing surface in the block. 

A friend in our local car club asked me about this issue a few weeks ago.  I relayed the problem to him. This morning he showed me a Cardone rebuilt YBlock distributor he purchased within the last few days.  Upon inspection, I could see that the distributor gear had been relocated.  They redrilled the shaft and relocated the gear.  Enclosed in the box with the distributor was a diagram and instructions on measuring this critical distance.    It looks as if they may have fixed this problem.  My friend will be installing the distributor soon,  If he has any problems, I will report back.

Tell Him to make sure the Overall Length is correct. Simply relocating the Gear does not fix the fact that the overall Length of the Shaft is 1/4" too Short if they are still using small block Ford Ones. Unless they have found a Source for correct Length Shafts I doubt this Story is over..

  

We'll see.  I had one of those distributors in my YBlock for about 6 months.  It worked while it was installed.  I removed it when I found out about the length issue.  It's still sitting under my bench.  How long it would have lasted is anyone's guess.

I assume yours was short? 5 3/4 instead of 6? Make sure His is not the same. The Short Shaft Ones will work for while. They are supposed to sit on a Support Pad inside the Block and the Gear is supposed to mesh with the Cam Gear at correct Height. Redrilling the Shaft and moving the Gear only fixes One problem and if its drilled only 1/4" lower than original Hole it weakens the Shaft.

  

I can see that.  The shaft I saw today had two holes, one with a pin and another with what I assumed was the original hole.  This might work in an engine without much stress. My friend paid $70 for this latest Cardone rebuild.  My engine now has a stock 1957 distributor. 

I would not use it at all if it is too short.  In Mark's original thread it was determined that it just barely engages the oil pump shaft, if it does at all.  I would not risk my entire engine with that.


Lawrenceville, GA

That's right. There's not a lot of Oil Pump Shaft Engagement even with a proper Length Shaft. Minus 1/4" and there's not much at all . 

  

I ran into similar. The "short shaft" distributors will work, but the wear pattern is wrong, and the key point is the gear uses the machined surface of the pad in the block as a thrust bearing. This is important. Any distributor must have the gear located accurately.

The thing with the drilled shafts, it's OK to drill new holes. In fact, once you start rebuilding a distributor it cannot be avoided.

A worn distributor, and that's all of them by now pretty much, has to use a new distributor shaft for a decent rebuild. Bushing replacement alone won't get you there, and the replacement shafts are never supplied pre-drilled for the gear itself. For some reason, the gears themselves are different dimensions (height); and there is no uniform location for the pilot hole either, so the point is further moot. So in effect, each distributor assembly is a "custom job". It has to have the gear located accurately.

Old gears have excessive backlash too, this interferes with ignition. I Suppose an old gear could be installed on a new shaft, but why bother? It would still need drilled and located accurately, within .005". Point being, the dimensions are critical.

So for another example, say a new gear were to be installed on an original distributor shaft, it would also 9 times out of 10 not be anywhere close to the correct length spec. This is more or leas why the Cardone ran into trouble.