newhouse

Hi, I am new to the site and this is my first post, I want to hook up a tach to my 1991 and I have a dash tach that I removed from a 1992 wreck (it was plugged directly into the factor wiring harness with a 4 wire flat plug), I have read through alot of posts on this and if I have this right my truck does not have a crank sensor and therfore I can't just plug in this tach. Question: Should I add a crank sensor and use this tach or get rid of it and get the alternator type such as the autometer??

wannadiesel

Get the alternator tach. You'd need to put in a '92 or '93 PCM and all the wiring to make the factory tach work. The factory tachs sell for some pretty good coin, so you will be able to buy a couple alternator tachs for what the factory tach will bring.

newhouse

Thanks Dave, sounds like good advice.

dpuckett

Another option if you get an ISSPRO tach is a sensor on the harmonic balancer, similar to the ones in the newer style engines. They both have their pros and cons.

Daniel