i've been trying to get the best performance possible with preimum fuel. initial 8* total 32*. i've been readjusting the vacuum with a adj. can down to what i think is aprox. 6* and still get ping on part open throttle. it's an 11 to 1 comp. big block but the cam's designed to bleed off compresion at low rpm's. i guess my ques is do i need the vacuum adv? and what rpm would you suggest to bring in the mech?

the darn thing runs good w/o ping in the evening when temp's. drop.
not a simple subject, apperciate any help.
john...

What rpm is your total in by? What rpm do you get ping? Do you know how much vacuum you have at ping and how much vacuum it takes to get 6 degrees?

John I send you an email
Ed

the total is in by 2800 rpm's
the ping happens when i try to accelerate, say in 4th gear to pass someone. low rpm, maybe should have down shifted. (make sense?)
as far as the vacuum needed for 6*, i'll have to check that. it's hooked to a ported source so it must be partial throttle. thanks john

never got an e-mail from you, it's john6066c@aol.com
thanks for the help, john