Helping a buddy get his truck lined out so we can take it to grudgement day. The truck is a 388 sbc single 88mm vs turbo big fmic blow thru carb deal with the msd programable 6 box. My question is I got the afr at a steady 10.7 on the wideband and pulling the timing down to 20 degrees at 10# but the truck is breaking up on a pull any ideas? I know it's still a little rich but didn't think that's so bad to cause it to break up. Has 3924 plugs gapped at .020