I think the RPM gauge is different between 90 and 91-94. So you can come over and try it out, if all gauges work and the tach doesn't you would need a 91-94 tach. I don't know if that's the only diffence between the two but you can give it a try. I'm in St. Petersburg off 275 and 38th, let me know. PM me a number to reach you at.