Listen to the Dirt Track cars (Texas Style--JunkYard Parts) there using a SBC 400's with 283 forged cranks, high compresion 12-14 pistons. They make 10K lap after lap and sound pretty sweet. This setup gives them something like a 4x2 setup 4" bore 2" stroke. They can surely rev. Gotta get main inserts, longer rods, anybody got info on this setup...These ole boys are tight lipped on there setups. Not quite MagnumPI sound, but sweet to my ears.
http://www.youtube.com/watch?v=wd85a67KIX0&feature=related