This is probably discussed somewhere in the site, but I'm lazy. I have a 90 Sub and ditched the 700/208 combo for a more worthy 465/205 setup. The t-case came from a 76 p/u and has the mech speedo output. I bought an adapter from Summit racing and thought it would be an easy install. My chiltons says there should be wires of one color and when I crawled underneath, there was something totally different. I hooked it up to the wires that had been attached to the 208 (not the ones for the 4x4 light) and still no motion on the how-fast gauge. Any help?