"used test/d-bol at that dosage and gain 47lbs, but only kept 25"
i find this hard to beleave, but once again to reiterate what i said preveously, the amount of muscle he will gain and keep will be determined by his effort and his genetics, there is no rule of gains that can apply to all people. some react good to androgens some react good to more anabolic compounds, its all about genetics and you effort.
however, if you was your friend i would run test 500-1000mg/week with some trenbolone (fina) 75mg/eod or ed. skip on the dboll. the theory that works good for most people is to have a strong androgenic base (test) along with tissue generating compound (trenbolone or deca)