Oh wow 454 thats pretty crazy. Right now im only making 320 hp with 882 casting heads. Which i believe are the L-82 smogger heads the casting number is 333882. Im using the GM goodwrench 290hp block. I read alot about if i change my heads and cam setup i should gain tremendous amounts of hp upwards to about 50-75 hp. i want about 400-450 hp. Also i was wondering if i wanna make about 400-450 hp what kind of other mods could i be doing aswell to help achieve my goal? Right now im running edelbrock performer rpm intake, headman 1 1/2inch headers with a 2 1/2 collector. 2.25 exhaust with small glass packs on. Holley 570 cfm vacuum secondary electric choke street avenger. CSR highflo water pump. Moroso Crankcase Evacuation System with catch can. Any suggestions will help so much. Thanks alot guys . Prox