when i throw my dwell meter on it's all over the place, new points, did a fine job last time. any ideas?

 

This is usually an indication that the upper bushing in the dist is bad.

Red

 

I would have to agree, your distributor shaft is wiggling around and causing the inconsistant dwell.

 

1. worn, wobbly breaker plate
2. excess end play
3. worn bushings

 

heavy sigh, guess i'll go looking for a rebuild kit.
thanks
greg

 

Check to make sure the condenser is tight. That happened to me and I was ready to replace the distributor when I noticed the condenser was loose. I'll keep my fingers crossed for you.

 

The distributor is the most ignored component on the engine. Guys spend thousands overhauling engines, but never even think about "blueprinting" the distributor, and if it doesn't work properly the engine will not run well.

Unfortunately, they were often indifferently assembled and now have 40 years of wear. Most installed distributors today probably need an overhaul. The key issues are to shim up the end play to two to seven thou, make sure the breaker plate is snug and wobble free, and use the high breaker arm tension points in engines with redlines over 5500. The centrifugal and vacuum advance should also be checked and characterized to be sure it is suitable to the engine configuration. This can be done on the car with a dial back timing light and Mightyvac.

The parts are relatively inexpensive, common to millions of GM engines of the era, and readily available.

If the bushings are okay, then the job is a piece of cake. If the bushings are worn and need replacement the distributor should be sent to a specialist for new bushings.

The overhaul procedure is in all the shop manuals. Just remember to install the drive gear with the dimple pointing the same direction as the rotor tip. For some unknown reason this step is not in the manuals, and if you get it backwards you won't be able to time the engine properly as many have found out.

Duke

 

Had the whole story.....