Engine leaning out at 3000rpm

Well i changed the valley pan and gaskets upgraded to a single plane m1 and nothing changed so i got to looking at the timing and lo and behold i took the distributor cap off and it had white corosion on all the terminals i scraped it all off and it ran great that cap dont have 3000 miles on it! But i guess they dont last to long i ordered a new cap and rotor so i will see tomorrow if it fixes the problem for good oh and i love the single plane that thing pulls like an animal i didnt perceive any loss on the low end at all the thing is a monster but i guess when you make 609ftlbs @4400 rpm you can afford to loose 15-20 lol