just did a gsr cluster swap into an eg. it woked and every is fine. when i pushed it up to 8k it sounded weird. like a rattle or something to that sort. can the stock tach be wrong? am i over revving it?

 

Stock tachs are notoriously wrong, but your probably not over-revving by much +-500 rpm, and if you are smart you kept some sort of redline on your ecu and didn't remove it all together. Though I don't suggest you go get a 5inch tach. And be careful when you buy an aftermarket tach. Not all are created equal. Infact most cheapies will be as wrong as your stock tach. And the higer end ones you need to be careful if you are buying a digitial or analog input.

Oh and the rattle. Since you haven't told us much about it couldn't tell you what is wrong. Keep an eye on it.

 

on both of my GSRs the tach is off by 500 RPM.. I have to take it to 8700 to hit my stock 8200 redline..