I'm trying to find out what the correct red and yellow lines are on the Tach for my 72 LS5. It has Auto & A/C if that matters. The tag for the part # is gone and I'm curious if it's the right one. I can't find any info in any of the books or manuels I have.

 I found some tach's listed at Davies corvette  they show a 72-74 LS5 tach with the redline at 5500 rpm the yellow looks like it starts at 5100 or 5200 rpm its hard to tell from the picture on the yellow line hope this helps

I haven't found anything either, that is absolute. I have pics of the dashes on some, but I can't really make out the red/yaller lines on da tach...
I'm sure there are some members here with LS5s....where the heck are ya'll????

The one that was in it is like the one EdMan is descibing. I went ahead and sent it to corvette instruments to be refurbed. I hope to have everything back from him in a couple weeks. Over the weekend I put my new tilt/tele column in with the new firewall insulation and new dash wiring harness and even almost finished my carpet. Waiting on dash. I gotta get ready for Hot Springs.

Can't speak for the 72, but my 71 LS5 yellow lines at about 5,200 and red lines at about 5,600.  At least that's what it looks like.  Hope that helps.