GR8RALLY,
I got these links off Andy Dunns Site.
www.cobralads.com
Here are a couple links. Just enter your car's wieght and desired ET and it spits out an estimated RWHP. That "should" get you started.
First link
Second link
However:
When all is said and done, I have to agree with dboothe. Things are not as easy as plugging in a few numbers, clicking the calculate button and buying the engine you need. Low ET's start with the driver and end with the road. If you can't hook up, then all you're doing is making a lot of noise for the crowd.