I had bad luck with autolites....they are a great replacement for the street but performance wise...not so much....get some NGK's or AC's in might help you with the break up thing...as far as falling on its face @ 100feet...that sounds like a fuel restriction someplace....what is your fuel pressure when @ idle...or when going down the track glance at the fuel pressure gauge and see where it is at...I bet it is falling off about then....