is the progressive mechanical secondary kit the only way to upgrade? was/is there a spring change to bring them in earlier but still stay vacuum? since I changed the rear gears, the RPM's climb slower, thus it seems like it takes longer for them to open. I think the mechanical kit would be better, but just checking options. any testimonials would be welcome. Bill
Edited by - SixT5HiPo on 08/22/2009 23:14:17