makin a hot rod

ive got a 90 s10 that i am in the process of installing a vortec 4.3 with a high rise intake and an eldebrock 600 . Ive resoleved the fuel delivery issue and am on the verge if acomplishing the spark issue. Any other suggestions to increase the HP are greatly appriciated.( headers and duals are already planned)

Please search, we have covered this 100s of times.