Mechanical to electrical speedometer conversion.

[MYVHV8]

I did a search on this and came up with nothing so i'm sorry if it's been discussed before but I gave searching a crack lol.

Ok so I have a VH trimatic backed 253 and I have recently upgraded to a gauge dash and have purchased a VDO Electronic speedometer.

So I need some sort of sensor to convert the mechanical signal to electronic and i'm not sure how to go about it, the only product I could find was one Autometer make a "hall effect sender" and when I asked the company if it was adaptable to my situation they replied "its made for Autometer gauges and we don't know if it will work for you." So i'm in need of some assistance. Can anyone shed some light?

Thanks in advance, Daniel

[eaton v8]

maybe v6 conversions could help i know they do a kit that goes from elect to cable so who knows