If you want to increase the power of the hp 500,depending on static compression ratio,I would recommend a high quality 871-1071 blower.I like littlefield or Kuhl.If you can get an intercooler from PFM,it would add at least 75 hp.2(800-850-cfm) holley carbs and an msd Ignition.Blower cam would aid Idling.Quality exhaust system is a must to achieve maximum torque.I have heard alot about lightning headers.How old is the engine?If you go with a larger blower you can use it for a future upgrade to a larger cubic inch engine.Can this drive handle the power? Maybe this should be addressed before you upgrade the power.Read the previous posts about carbs and boost.I am assuming the compression ratio is not more than 9:1 on the hp 500.Is this motor going to be rebuilt?You will receive more suggestions,so a little more info on whether you intend to just bolt this stuff on and go or rebuild the engine.If the latter,I can give you some good tips on parts choice.For example,If you do rebuild the engine,installation of low compression blower pistons would help you run more boost than stock pistons.More boost = more torque,to a point, then other factors come into play.There are some people on this forum with more expertise than I, but I have 2 supercharged engines that I have learned much from.Good Luck! DEL51