I am running a 24 plug gapped at .035. I started out with my timing at 8 degrees and I'm running it at 9 now. The rule of thumb i believe is to take out 2 degrees for every 50hp of N20 you're running. I like to keep my car on the safe side so I just leave it where it is. Make sure you get a new fuel pump too. I'm running a 190lph, and I set my fuel to about 45psi. It's a bit rich, but it's not gonna blow up. The plugs always look perfect, so I'm assuming it's probably where it should be. Hope this helped.
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94GT
Mac Headers, BBK Off-road H-pipe, ASP Pulleys, Pro 5.0 Shifter, 4.10 Gear, Weld in subs, Flowmaster 2 chambers, NOS 150 shot. Best ET 12.34 @ 110.