Tach not working after changing plug wires

Well I tackled getting new wires and extenders on my 79 308. But when I went to start it it would barely run, seems like one bank was dead. I lifted the rear deck lid and took a look at the coils and when I went to check the black ground wire from the distributor, it pulled out and fell off from the copper connector. The engine died immediately. I noticed the manufacturer did not crimp the connector good enough. So I decided to take a look at the connector to the rear distributor, the one on the bottom. I was shocked to find it was disconnected as well. The dam thing pulled right out!
So I then proceeded to disconnect the rest of the 2 ground wires terminals from the kit and put 4 new connectors on.
Once I completed that it fired it right up! Smooth running but no tach.
Maybe I bumped a wire loose while I was working around in there but I don't know.
I am frustrated about the less than stellar crimp job on the wires that I received from the vendor, but I know now that mine aren't going to come off!
Any suggestions?
Thanks in advance
John

 

Ok. I found that the brown tach wire slipped off of the stud on the coil when I was repairing the the coil wire issue. I put it back on the rear coil and the tach seems to be working at idle. I could'nt get it out of the garage to test last night.
Does it matter which coil it it attached to??