an 88 or 89 cluster fits the 88-89 and the 90-91 fits a 90-91 wiring is different and th cover is different. I got one from an LX 4 door. the readline is 6,500 and my ZC redline is 7,200. but it only cost me $25 from a U-pick-it. I have an '89 DX converted for MPFI with the DOHC ZC engine and tranny. You need to know what year the Si cluster is, unless you are prepared to do the wiring.