Any check engine light? Did you change the timing belt? Maybe you forgot to plug something back in. Check if you plugged in the hose for the IAC valve to. You also say you can't go past 3500 rpm's. Were any of these issues there before the gasket rebuild? Could be a CAT. Could also be a valve. Get ...
So I just did a FULL gasket rebulid on my motor..91 sport sedan.. list of things new.. Spark plugs plug wires coil pack starter fuel pump fuel filter SHe runs fine untill she gets to running temp, and then she starts to idle really rough and when I come to a stop..she almost dies..I cant go past 350...