I am getting my car ready for a dyno event coming up on Oct 25th. Well currently I am running Autolite 104 spark plugs with a 0.54 gap with the setup that is in my signature. This is currently on a 2.7" pulley, stage III IC, 11.8 AFR, and 18-19 WOT timing that I haven't increased since dropping it a few degrees when I went from a 3.0" to a 2.7". My plan was to bump my timing back up close to what it was with the 3.0 pulley which was 19- 21* because I haven't seen any KR what so ever since the pulley 2.7 pulley swap and 18-19* of timing. I also have a 2.55 pulley I would have liked to try out but without an 8-rib or belt wrap system I think I am going to run into slipping issue's.
My spark plugs have close to 16K on them and I wanted to swap them out for newer replacements before going onto the dyno.
The funny thing is now last night I did a WOT pull and I felt my car misfiring at certain RPM's. I didn't have my HP tuner in the car but according to my Aeroforces I didn't notice anything out of the ordinary or KR. So I think this is also an indication that my old 104 spark plugs are starting to wear out? My stock AC delco wires have around 24K on them. I really hope its a misfire and not my transmission slipping. That only had 17K on it!
Anyway, a few days ago I picked up another set of Autolite 104 spark plugs. However I have always been told that with my setup I should be running Autolite 103 spark plugs? However if I saw no KR or misfires with 104's gapped at 0.54 should I just keep it the same setup? Or should I step down to 103's and push for even more timing?
A few members have suggested that I go with Autolite 103 spark plugs and gap to 0.45-0.50.
I also was given this guide from another member and this is what they suggest:
Guide to Spark Plugs - 3800Pro.com Forum
Intercooled
3.25-3.0” pulley: Autolite 104 @ .050-.052”
2.9-2.7” pulley: Autolite 103 @ .046-.048”
2.6-smaller: Autolite AR94 @ .044-.046”
What should I do guys?
