6 cyl tach?

[bucket]

i want to add a factory tach to my dash for a 6 cyl. did the factory tachs have a switch or filter to switch between the two? parts suppliers only list v8 applications.

[Bob B.]

The G.M. parts books listed 2 different numbers for 6 and 8 cylinder tachometers. I was able to have a speedometer shop recalibrate a reproduction 8 cylinder tach. to work with a 6 cylinder. The reproduction I had did have a calibration adjustment screw on the back, and there was enough adjustment to make it work with the 6. I don't know if all the reproduction tachometers are the same though.

[396muncie]

I had a factory 6 cyl tach and no, there was no switch or filter. It looked just like an 8 cyl version minus the "8 cyl" stamping on the back. Good luck finding one.

[Huck]

6 cyl tach's are around with a unique part number. The potentiometer adjustment on the 8cyl tach might give you enough to work on the 6cyl. Or, you could install a marine tach ie. Mercury makes a tach for 4,6,8 cyl selectable and it looks like it would fit fine in the truck dash. I just picked one up brand new and may try to set it up~~~.

[GMC Jim]

I used a 0-6000 marine tach.... installed just fine with some modification..... was for 4-6-8 cyl engines.... will try to find pic if anyone interested........Jim

[bucket]

i would like to see that pic

[GMC Jim]

Pic of marine tach I installed 10-15 years ago.....I have always believed in Marine instruments, gauges, switches, solenoids etc., to be of better quality than equivalent auto/truck applications. Brass cases, glass (instead of plastic lens)..cases filled with inert gas ( argon, etc.) In general marine products are pretty much moisture proof for long life in the damp/wet marine envirionment.
I do recall that I cut the printed circuit to clear the tach body.... soldered the cut traces enabling a U shaped printed circuit to clear the tach.

[GMC Jim]

BTW. the tach I installed is 0-6000 RPM