I have an EF fairmont with a six and auto which has run 16.4 but feels very sluggish of the line. I will shortly be replacing the diff gears for 3.7 (would these be the best as it does go on the highway a bit) and am considering changing the stall conveter (worth it or not?) plus the mods listed below. I'm after some cheap (free) improvements so for the next run lots of weight will be removed plus some premium unleaded and octane booster will be added. Will I get any improvement by adjusting the timing (if its possible) if so what would you guys recomend?