I bought an ecu and it was supposed to be 8500rpm, but a 9k was shipped. I asked how reliable it would be and the guy told me he has had them on his cars for a long time stock form. He said I wouldn't want to climb that high boosting above 10psi though on stock internals. I have been driving this thing for 8months without any issues and I keep the fluids checked, so it seems fine.