A daily driver 500hp small block is going to cost you coming and going. First, building a real 500hp engine aint gonna happen using the machine shop services of the local NAPA store....you're going to pay to have the detail done. Then, when you get done with this expensive motor, you're gonna wear it out driving it to the 7-11 and to work? Gonna cost.

Here is a link to a 500 hp small block. Only $8500.

http://www.theengineshop.com/engine.shtml

Plus, with 500 hp, you will need something more than a home brew TH400.

You can build a 400 hp 350 for maybe $4000 or so if you stick to basics.