Here is some new technology that will soon be available to tickle the fancy of all the owners who want POWER!

http://www.coatesengine.com/index.html

A stock-block 4.6L modular was equipped with a set of Coates heads and easily churned out 426hp without even breathing hard. Change to a forged crank, H-beam rods and forged pistons and rev the thing to ten grand or more!!

I don't know what a set of heads would cost, but I should think they'd be priced no more than a hot crate engine.