The magazine has A 5.3 build up. Cam, heads, headers, and HPT made 441 hp at 6200 and 410lb-ft at 4800. They said it was 97 hp gain and 40 lb-ft over stock. Cam= comp cams xtreme rpm roller 220/224 .530/.534. Heads= edelbrock rpm xtreme 65cc combustion chambers, 214 intake runners, 80cc exaust runners, 2.02 inch intake valves, 1.57 inch exaust valves. Headers=hooker supercomp Lt's.