I have a 79' chevy 1/2 ton 4x4 pick-up, I replaced many parts and upgraded parts like , carb,headers,intake,etc......My problem is ,I hear a spark knock at high speeds or climbing hills. How do i eliminate this noise. Is there something i overlooked in my upgrades, or is it just fine tuning the timing or ajusting the carb??????? I need help??????



How loud is the noise?
the noise sounds like a bad gas sound , not very loud but very annoying,, i have headman headers and glass packs with staight pipes to get an idea, and i can hear it from inside the cab,,,,,,,
Is it an original 350 from 79 in your Scotsdale? If so, how many miles, etc?
Some people call me the space cowboy ... some people don't.
2010 Chevy Silverado Z71 Just picked it up
2007 Chevy Colorado Just traded her in!

Are you hearing the knock mostly under load? I agree, more information on the age/condition of your engine will give some clues.
John ~ New Mexico ~ It's all about the bowtie!
2007 GMC Envoy & 2010 GMC Sierra




You can back the timing off a little or try running a higher grade of gas. Either should help, but the gas is the easiest to start with.
Gary
99 K 1500 Suburban
78 Silverado Big 10 w/factory 454
1977 Formula
1976 Trans Am
1980 Honda CB900 Custom



Yes, it's always best to start simple. Keep the tank full, try a different brand with different additives and higher octane, etc.



any news?
Steve
02 Chevy Trailblazer LS (110K+ miles - loaded except for 4WD - WRECKED!)
99 Chevy Cavalier LS (105K+ miles - commuter car)
78 Chevy Suburban Silverado (454, 3/4 ton)
62 GMC 3/4 ton Pickup (350 police interceptor)
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