340 Horsepower ?

I Do Have A 508 Cam Some Where In That Garage New Lifters And A Set Of Roller Rockers But Still Wondering About A Hp Fig. Guess Ball Park ? Also With Decked Heads Should I Use Lifters Sup With Rockers Heads Where Min Cleaned ALSO CHECKED COMP ON MOTOR 5 WHERE IN 200 RANGE 3 IN 175-190 RANGE BLOCK IS A BIT OLD ON REBUILD 150,000 OR SO