I have a couple of questions to ask on the installation of my new dist. I just purchased a new zz502 crate motor and I'm not sure how the advance stop bushing works. The dist comes with a 21 degree already installed. Do I need to change this to a larger or smaller. I know my total timing should be about 36 or 38 degrees. Do I add the 21 for centrifugal advance and what ever I have for inital timing to get my total timing? Second question is the dist. comes with two o-ring installed on the shaft of the dist. It says to only use these if the block has been champfered. Do I remove these on a zz502 motor?

If you want to set your total timing to 36, and your distributor is giving 21 mechanical advance, then you need to set your initial timing to 15.

Regarding the second question, I have no idea.

-gw

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1967 Camaro
406/M20 11.94@117
http://www.mindspring.com/~gordon.warren/

Hey there... I am running an MSD billet in my '69. I hope I can help you out.

First of all, the 21 deg. is the installed bushing and is a fairly good starting point. When you get the car running, you can mess around and change the bushings to see if the engine likes more or less mech. advance.

Secondly, you might be able to use the O-rings on your 502. Lube them up well and see if the distributor will slide in. Don't force it. If it does, pull it back out and inspect the o-ring for cuts or tears. If it looks ok, then I would say you are good to go.

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Steve - Central Ohio Camaro Club (http://www.ohiocamaros.com)
'69 Camaro RS/SS-350 - Daytona Yellow
'95 Camaro Z-28 - Sebring Silver
click here to see my webpage ---> My Camaros (http://www.mindspring.com/~mccorry) (updated 11/5/01)

I also have the msd billet dist. yes, you add the initial timing you set to the 21 to get your total but also look at when you want the total advance to come in because you can just change the springs to get earlier rpm total advance. I think it comes with the heaviest springs in it to start which comes in at around 6000 rpm. my 327 seems to rev best with the total advance at 3k - 3500 rpm at 35 deg.

I thought the MSD distributor had a pretty good discussion of how to determine which springs you should use. I would follow theirt directions there. I have a 350 have all of my timing coming in before 3,000 RPMs too.

I have an MSD system on my small block. And if it were me, I would take the distributor along with the little bag of stops and springs, to a good shop with a distributor machine. Take the cam card or the specs, tell em what gear and converter, and have them curve it. Then after break in of the new motor time the motor for or at total advance. And you'll great sucess.

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Black 69 camaro