Well, if you're not doing an engine swap, then the basics of internal combustion engines come into play. Get more air in and get more air out. With the carb and header you'll be helping that scenario, you can also do things such as bore an stroke the motor, put a different cam in, port work, turbo, etc etc etc. Just ideas. But with the platform that you're starting with power will be kinda on the low side. Hope this helps!