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.
aneone know of a site i can buy one from? i live in domestic land, it took me 7 different junkyards and a week to find a damn head light, and they still gave me the wrong corner lamp. I believe that no one could find my model year even though its a 12 year old car. I doubt Ill find an Si.