What would be most recommended for a 340 4-speed car. Will have the Comp 268 cam (unless other is suggested) and 3.55 rear - why double-pumper over vacuum (if recommended) ? Thanks. I have a 670 Avenger (vacuum) that I can use - but not sure if that's what I want on a 4-speed car. I'd like to have a high 12 sec car but not sure if doeable(sp?) with the 3.55.
