I'd go for the 408 buildup. If you're into needing pistons already, that is a big chunk of the difference in a stroker kit. I did a eagle crank and H beam kit through board member Scott Brown. My only reservation might be that you need to make sure the heads flow for a stroker, or it might run out of steam earlier than you want it (even though it's makign more power), and if you are geared for a screamer motor, you might have to re-gear for a bit less RPMs or make the 408 a screamer too. Mine makes peak power in the 6500 RPM range but it's built to make lots of power up there.