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Old 10-13-2008, 12:47 PM
red65mustang red65mustang is offline
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agree with bogie,

simple step one is to test for timing chain slack/stretch and dist mechanical "slop" from use....

rotor pointing at a mark on the body, use a breaker bar and rotate the crank a bit in both directions to confirm the rotor moves instantly=chain is tight....
(that's why tune up spec's will often say add 2* to the original base, 6* on the damper isn't 6*'s any more due to chain stretch)

on a stock motor, with a tight chain the usual/typical spec is: "you can add up to 5* base max more for better performance, more than 5* will not help performance"
(your base was 6* so there is likely 28*+ worth of cent so 12*base + 28*cent=38* + 2* of chain stretch(?)=to much)

I'd set it at 10* and then start testing the dist cent curve with a timing light, worn/weak springs (=to much to soon) and tall rear gears may be the root problem...

the CA smog specific vac advance unit calibration may be part of the problem, test drive for ping with the vac advance disconnected and plugged....
(it can be adding to much to soon)

to know how many degrees of cent, with the base at 10* read the timing (vac unplugged) at 3500+,,,total timing at 3500 minus base=total cent....
for "no ping insurance" I would set the base for a max total of 34* at 3500

decent totally mechanically rebuilt dist (cent plate/bearings/gear/new points/condensor/etc/etc) dist is only roughly $50?
it's imperative for WOT blasts that a dist is "dead on" mechanically to work correct...
suggestion:
take your dist to a local parts house and compare it side by side at the counter to a fresh rebuilt for wear "slop"....

later, after you have used up the new points some, swap to a Pertronix solid state ign module ($70?) (always 28* dwell and more energy for a longer period during the spark event)
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