I'll be back to it in a few days and I will let you know what I did to make it work on my 93. How do you plan to fix your speedometer input? The LS1 uses different pulses per mile than the 89 Chevy did. You have a yellow and purple wire coming from the trans going to the gauges that drives the speedo and cruise pulse counter. My 92 is a little different than the 89. My buddy has an 89 and we are putting my old LT1 in it, we will address the cruise issue on it in a couple weeks. We may have to work around the issues with the cruise but it was simple in my 92. The 2001 PCM has an output level to drive the speedo and Allen has it working good on my truck. I assume you will have to find the common lead that feeds the pulses signal for the tach/cruise signal on your year model. The two wires mentioned earlier have to go somewhere to convert the pulses to a signal the speedo and cruise can count.