[greguw]

I would see if you could gut a HEI and remount the pickup , but not sure if it will sense off the bolts . I used a Autometer 5211 ... think its the diesel probe .
Where the crank area is the fan will make contact . I was going drill and tape the outer edge of the harmonic with 1/4 bolts and go that route .
You just need 4 pulse for the HEI to generate the signal ... its like a 4cyl ... tack just knows its getting signal .
I have my pickup set at the outer edge of the bolts but did leave some room for adjustment if need be .
I also set my gap at .040 . The picture is of the second design mount . The first attempt was ok but thought it might viberrate , I basiclly welded a arm to the original tach mount .