Could have been the billet wheel was out of balance or could have been something to do with the installation of the wheel. 38r is a good turbo and they can be found for 1249.00. to your door. If you don't already have a ebpv ******/high flow housing on your 38r and you plan on doing that the KC38r may be a better deal for you. If you want retain the Ebpv or already have a high flow outlet I'd roll another 38r. Also choice may depend on the cost to have a KC38R rebuilt once out of warranty, if that's a deciding factor for you.