New 8k tach dash not reading correctly

[Todds69]

I bought a new complete gauge cluster from brothers with the 8,000rpm tach got it all hooked up and it reads at least twice the rpms that the motor is actually turning. I have all msd ignition, pro billet distributor, blaster coil, and 6al box. The tach is plugged directly into the 6al box like it's supposed to be. Anyone else have this issue? Are these gauge clusters just that crappy?

[68c10airstream]

I removed a repro 5k tach and installed a 8k tach. My tach signal was corrected by member "critter" that works at lonestar dyno in texas. I have a 5.3 ls in my 68 and the pcm can be rescaled to read correctly, and you neeed to match the signal, v8 for v8, etc.

[Todds69]

I don't have an ls motor or efi. I'm old school i have a 406 sbc with all msd ignition. I'm sure someone somewhere has had the same problem as me

[pinturbo75]

some tachs have a selector for 4,6 and 8 cylinder operation..

[Todds69]

There is no selector on this tach. It's a factory type gauge cluster with a factory in dash type tach.

[68c10airstream]

I suspected you were running a sbc. I commented to basically say the tach itself was ok and bring to light the matching of signal. I've never seen a comment on selecting a specific cylinder with a msd box but wasn't looking either. Welcome aboard to a great site!