Tack ?
 

What is the easy or best way to put a tack on my 91 :humm:

If you look in the sticky you will see a thread I did on an Isspro that I got. What year is you truck? You may already have a factory hook up and just need the tach.

Never mind. I see you have a conversion. Read the thrashes in the sticky. That's you best bet. I would put up a link but I'm on my phone. Maybe one of the other guys will put it up for me.

EDIT:

Here is the link...
https://www.dieselbombers.com/5-9l-r...uge-mount.html

Not from our sticky but I think It'll do ya,
Dodge Diesel - Diesel Truck Resource Forums - View Single Post - Questions about hooking up a Isspro tach
http://www.dieseltruckresource.com/d...d.php?t=236340
http://www.dieseltruckresource.com/d...d.php?t=173561
http://www.dieseltruckresource.com/d...d.php?t=185725

Real easy install.

if your truck already has a tach in it (i dont knwo if they did or not in 86) use the chevy alternator its already wired for a tach input. if you dont already have one on the dash just go aftermarket