just to clarify, when he says you just change the speedo assy, you dont change out the whole cluster, most of the other gauges won't work if you do, you have to actually pull the speedo part out of the cluster assembly and switch it into yours. and it's not exactly true that you have to use a matching one. i have a 140 speedo out of a 92 (airbag car) in my 87 cluster. just have to do some trimming to get it to fit.