got my rad out now all pulleys off, putting in eletric fan rear mounted battery. is it worth putting in underdrive pulleys or should i just keep the stock ones on, right now i'm up grading my alt to 100 amps. will new pulleys effect my charging system. what do you guys think i should do, its all apart now so i can just order them now.think march has pulleys that spin a little faster. my car is a 69 mach1 408 windsor.also i see a little oil under my front manifold right on the front of block i used a sealer when i put on the stealth could it be a vaccuum leak there should i take it off and do it again, while i got it apart.looks like a drip going down the front of block right behined the distributor.i know this is a long post,whats better air gap or stealth? street car thanks.