depending on the weather you should see 17-19 l.b.s.(in theory 8 l.b. stock+8 l.b. pulley+2 l.b. from 2.8=18)although i would not suggest the upper unless you have a adjusteble tensioner or you will get belt slippage.(plus it is really hard to change)i am guessing this lightning if it is a h.d. take off 2 l.b.s. of stock boost.