# 69-350 Timing



## chin (Jan 5, 2011)

I've got the timing tape on the harmonic balancer, set initial timing so the "0" and hash mark on the tape line up to 9 degrees on the tab with the vacuum unhooked from the dizzy and plugged on the manifold. Then I plugged the vacuum advance back into the manifold, revved it up until it the numbers quit moving, and set the 41 mark on the tape so that it lines up with the 9 on the timing tab. I was thinking that this would give me 32 total. Or should I set the 41 so that it lines up with 0? Pretty sure after reading through a bunch of posts I should be at about 32, I'm just confused on what mark on the timing tab I should line up to what degree on the tape for total. Appreciate the help!

Setup - 69 pontiac 350 that is stock other than a performer intake, 600cfm edelbrock carb, and hei ignition.


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## BearGFR (Aug 25, 2008)

chin said:


> I've got the timing tape on the harmonic balancer, set initial timing so the "0" and hash mark on the tape line up to 9 degrees on the tab with the vacuum unhooked from the dizzy and plugged on the manifold. Then I plugged the vacuum advance back into the manifold, revved it up until it the numbers quit moving, and set the 41 mark on the tape so that it lines up with the 9 on the timing tab. I was thinking that this would give me 32 total. Or should I set the 41 so that it lines up with 0? Pretty sure after reading through a bunch of posts I should be at about 32, I'm just confused on what mark on the timing tab I should line up to what degree on the tape for total. Appreciate the help!
> 
> Setup - 69 pontiac 350 that is stock other than a performer intake, 600cfm edelbrock carb, and hei ignition.


Sounds like you're close - one thing: setting "total advance" almost always refers to total _"mechanical"_ (centrifugal) advance, so you should do the process with the vacuum advance line disconnected and plugged, both at idle and at "speed". "Most" stock Pontiacs with factory cast iron heads "like" to be in the neghborhood of 34-36 degrees total (vacuum line disconnected, engine at or above 2500 rpm to make sure the advance is "all in", line up the "34" mark on the tape with the 0 mark on the cover, clamp it down.) On a dyno you'd start somwhere around 32 degrees or so, advance it two degrees at a time making pulls and taking measurements until torque and power start to "fall off", then back it off a degree, if you wanted to really dial it in.

Bear


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