One of the ones on this page?

http://www.jagsthatrun.com/Pages/SpeedSensors_Speedometer.html

Straight to the ECM, or do I still need some huge board to stick someplace?

Quote Originally Posted by EagleMark View Post
1227747 ECM right? Jaqs that run 2 ppm inline VSS sensor.

Your working on your Blazer right? If so you could look into a 1987 to 1991 Blazer, Suburban dash board which would have the VSS in behind the speedo. I've never tried this but they are same body style and dash looks the same as does most everything else. Someone may have already done it and you could check at CK5.org