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Distributor rebuild questions

3K views 12 replies 8 participants last post by  GtoFM 
#1 ·
I have a 1964 GTO with a '66 389 tri-power 4 spd. Engine hasn't ran for 10+ years. In the process of checking the distributor, p/n 1111054, the breaker plate movement seemed restricted. While degreasing, I removed a lot of gunk under the plastic cap (below the felt washer) of the Permanent Lubrication Reservoir. Was there any kind of media in the reservoir to retain oil, or was that just years of gunk build up? Pontiac shop manual does not reference anything. Is there a rebuild kit available that goes beyond the typical points, cap and condenser? I haven't been able to locate a local rebuild shop.

#2 , what's the advantage to change the gear to bronze or other material?

#3 , there are various vacuum assemblies available, how do I select the correct one?

Finally, I've seen charts that suggest factory p/n 1111175 as the "correct" distributor. Is there info out there that details the differences?

THANKS
 
#7 ·
Rather than fool with an old points type distributor that's tired and needs rebuilt, I recommend replacing it with a MSD Ready-to Run unit for a Pontiac. It comes with various springs to adjust the mechanical advance and a vacuum canister for manifold influence. It uses a magnetic trigger instead of points and never needs adjustment after being set up. If you don't like the red distributor cap, it can be replaced with a standard black one. The distributor will run with or without a MSD spark box.
 
#8 ·
Very simple to freshen up an oem distributor. Keep the original gear, if in good shape. (They rarely go bad). Note the dimple mark on the gear in relation to the shaft so you can install it in the same position. Knock out the roll pin, remove the gear, and the shaft will pull out. Now you can clean the shaft and distributor of varnish so it will no longer hang up when the centrifugal advance activates. You can install new bushings in the body (seldom needed) and pack the top area of the shaft under the felt with grease. Lube and clean the weights and you are good to go. I run original points distributors in all my old cars with zero issues. I don't mind replacing the points every 15,000 miles or so, and it's a great trade off for the reliability I get. (40 years and 100's of thousands of miles with zero breakdowns on the side of the road). New tech HEI is very popular, especially for those unfamiliar with points, but they are not as reliable.....and not fixable on the side of the road. Have seen MANY cars come in on a hook due to a bad module or pickup coil. Your car, your choice.
 
#9 ·
Thanks for the advice guys. I flirted with abandoning the points and going electronic but my driving days started in 1970. That said, I am with geeteeohguy and keeping it original to the engine. I am ok with points set up and care. It is cleaned up and and ready for assembly.
The gear has minor, but obvious wear. How do I know when it should be replaced?
There is .054 end play. I have the Moroso shim kit. The forum suggests .010-.015 but I dug up a 2007 post from Lars stating to shim it to .005-.007. I understand these are not as critical as other engine tolerances but the shim kit will put me at .004 or .014. Do you feel .004 is too tight?
 
#10 ·
Well, like so many things on a car, a lot of suggestions and personal preferences.

The distributor housing, along with the engine, will expand with heat. Tolerances too tight, and guess what happens? For me, I would want a little buffer, so .014 would be my choice.
 
#12 ·
Lars made a distinction between an iron distributor and aluminum version

Yank it out, shim out the endplay with Moroso part number 26140 (setting shaft end play to .005 - .007” for cast iron units and .010 - .015” for aluminum housings),
Since we're talking Pontiac and a cc rotating distributor (as opposed to a Chevy clockwise rotation) The tolerance is probably not as critical. As the distributor turns it's pulling the shaft down and closing the endplay as opposed to a Chevy which tries to increase the endplay as the distributor rotates.

Reducing the endplay will help when you go to time the engine. With a large gap the timing will advance significantly when you clamp down the distributor, reduced endplay negates that problem.

I'm also in the points camp. Less expensive and reliable for street cars.
 
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