Anyone running a 70 with an MSD and a Factory tach?Are you using an adapter?I have a MSD 6AL with a MSD 85551 Dist. and a MSD 8920 adapter.My tach seems to work ok up to about 4000 rpms,then kind of quits.Connections are good,just wondering if anyone else is running adapters or not.Tried hooking the tach wire direct to the MSD tach outlet,tach didn't work at all.

Try again.

Doug:

Just fired up my motor with the same set up. Have'nt had it out yet nor taken it up past 4000 but will look at it in a couple of weeks when we get the chance to run the revs up.

Thanks Mark,are you running a factory tach thru the adapter and is it working?

Yes to both. The tach is factory and it works with the tach adapter. Didn't try it without as we just figured we would need it.

I'm running an MSD 6 AL box on my 70 also. I don't have any adapters hooked up, just took the brown wire and plugged it right into the port on the box. The tach only works when it wants to, but when it does, it's fairly accurate all the way up to 6000 RPM.

Thanks guys,I guess I'll just have to pull the dash down and double check my wiring.I hooked back up to the adapter and now it's working worse than ever.:mad: