i have built two 383s. i used a eagle cast steel crank and eagle i beam rods with bused rod. 12.39 to 1 pistions a 306s comp cam team g intake,800 double pumper holley,dart iron eagle heads 215cc runners with 2.05/1.60 vavles. jegs has a good price on them they also have balance kit you are looking for. i drag race mine when i can it is 1980 camaro runs 12.56 at 109.50 in the 1/4 mile cant run it on pump gas but i do drive on street when i can it is alot of fun hope this helps you out if anymore help i will try to do what i can.