Hello everyone. I have a big block chevrolet that I bought assembled used. It is supoosed to be a 505 ci motor. 4.250 stroke 4.350 bore. It is a markIV block I believe. (70 model 454) with cast iron heads that the guy did alittle work to. I dynoed the motor mainly for tunning purpose. It came out to 548hp and 589 tq. I am wanting to upgrade to try and get some more power. Everyone keeps telling me to get a good set of aluminum heads. The only problem is Im not a mechanic, as far as figuring out what head combination will work good on my motor. I can turn a wrench. As far as my vehicle, it is a 8000 lb tube frame mud truck. I run it in the woods trail riding, not street legal. 54" mud tires on 2.5 ton axles. I have read alot of good info on this site about motors so I figured I would ask here. Is this something that can be answered without alot of info on my motor or do I need an experinced mechanic to open up my motor to see what i have. I know I have a solid flat tappet cam with a 517 lift but not sure about anything else. Would i be better off getting a cam, intake and heads all together. Any help would be appreciated before I go to a performance shop and some one see's me coming and gouges me to death. Another question, Is the investment going to be worth it to make a diffrence in what I already have. I only have about 4500 dollars in the whole motor. I really dont want to spend 3000-4000 more and only see a minor change in hp and tq. Thanks