Colder Plug Questions?
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Senior Member
Certified GM nut
Joined: Jul 2003
Posts: 1,712
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From: Chicagoland

So to go along eith my new Taylor 10.5 wires, I'm not to sure on what plugs I need. I know I can go one heat range colder, what about two? What'* the rule of thumb for mods and heat ranges? I will have rockers and headers by spring if that matters. Should I wait till those are on, then could I go 3 ranges? Whats the mileage out of all these plugs too.
AC Delco'* or Autolite'*?
Thanks in advance
AC Delco'* or Autolite'*?
Thanks in advance
I've heard something like 1 heat range colder for every 40'ish in horsepower gains. The colder plugs will just foul sooner because the engine is still running hotter, it just keeps the plug from turning into a glow-plug and causing pre-ignition which is the father of detonation.
Senior Member
Posts like a Northstar
Joined: Oct 2003
Posts: 514
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From: Greater Cleveland area, Ohio

I bought a 3.5 sc pulley, a 180 stat, a k&n filter in my stock airbox. Do you guys also recommend the one heat range plugs with this simple modification? I bought some delco'* already one heat range colder. Will installing then be better or worse with what I got? Mind you I'm picking up around 25hp'* and 40-50lb. ft of torque.
bought a 3.5 sc pulley, a 180 stat, a k&n filter in my stock airbox. Do you guys also recommend the one heat range plugs with this simple modification? I bought some delco'* already one heat range colder. Will installing then be better or worse with what I got? Mind you I'm picking up around 25hp'* and 40-50lb. ft of torque.
AC-Delco 41-932 or something like that i can find the plug number in a bit.
So to go along eith my new Taylor 10.5 wires, I'm not to sure on what plugs I need. I know I can go one heat range colder, what about two? What'* the rule of thumb for mods and heat ranges? I will have rockers and headers by spring if that matters. Should I wait till those are on, then could I go 3 ranges? Whats the mileage out of all these plugs too.
AC Delco'* or Autolite'*?
AC Delco'* or Autolite'*?
also haven't heard the best things about the Auto-Lites.
Speaking of overrating, how the heck are you getting 32psi?? I'm tempted to say you're talking about tire pressure, right? haha
lol
Taylor, I would run AC Delco 41-919'*. They are 1.5 ranges colder than stock and are what we ran on the GTP from when it had just a 3.4 pulley & CAI, until Sunday morning before we ran at the track when we decided to run the Autolite 103'* (3 ranges colder) to see if they would help. They did, so we left it that way. (I think the time it pulled is reason enough for that) The GTP ran a best of 12.594 @ 108.04 on the 41-919'*, so they are definately good plugs, just not quite cold enough for the 2.6 pulley on the GTP.


