Race blocks

if you got the money get a gen2 hemi. it can do 7 ,8 ,900 hp on pump gas. gonna cost you 18k-20k though, pan to carb(s)
http://raybarton.com/parts/index.php/engines/street-series-hemi.html

but to be honest, when you pay 5k for an aftermarket B or RB block, then your stroker kit 2k+, then all the parts and machining, etc etc you will probably be at 12k+ by the time you are done.