Hey guys I really need some help on my 98 mach z lt! last year I was running it stock with a 2x136 track it ran good but for where I ride I felt I needed more traction so I put a 2x151 and a set of JAWS PIPES on it and it runs awsome execpt for the top end. I have a purple, purple spring in the primary which is 160- 320 spring tension and I just rebuilt my secondary and put a new spring in it as well (beige spring) So all that is not stock is the primary spring, the pipes and the track I also dropped 1 tooth in my top gear. Now whats happening is that I pin it across the field and out of the hole it flys all the way to 70 M.P.H. at 8800 rpm then it starts to fall fairly fast right down to 8400rpm for the duration of the run. I have a straight 47 degree helix, what I'm thinking is to change that out for a double stage say a 48-44 what do you guys think??