I am trying to hook up a 3 wire VDO speedometer to a GM T5 5 speed transmission. The T5 appears to have a pulse generator with two wire and about 2 inches in diameter and the VDO p g is smaller and does not fit. I ordered another p g from VDO but they sent the same one I received in the box of gauges so I returned the p g to VDO. What part(s) are needed to make this work ? What is the fix ? Suggestions ? Sources ? Drawings ? Try a different brand ?
Go mechanical somehow ?

THANKS in advance !!!!!

BRAD