My old 355 SBC used to spin north of 7500 on Nitrous in our old'68 Camaro. Use to be a blast back in the early 80's. If you want to get crazy with LS Motors you can do something like this All Motor LS record Holder. Really have to hear and see this Car run in person over 9000 rpm.
http://speedsociety.com/1100hp-all-m...-aspirated-ls/