For a factory tach there is a tach harness you can buy. The factory clock connector is already there taped back to the harness when it wasn’t used.
It should be quite possible. I used an old clock housing. I had to cut out the back a bit. Your challenge will be cutting a nice clean hole in the delete plate and coming up with a way to attach the tachometer to the remaining delete plate. I might consider some type of epoxy in that case. 3 3/8" tachometers are what you are looking for. Autometer has some very nice ones. https://www.autometer.com/3-3-8-tach-8-000-rpm-in-dash-elec.html https://www.autometer.com/3-3-8-tach-8-000-rpm-4-6-8-cyl-designer-blk.html https://www.autometer.com/3-3-8-tach-8-000-rpm-in-dash-db-ii.html http://v8buick.com/index.php?threads/finally-took-er-for-a-ride.339221/page-6#post-2879949
So I am thinking pull out the delete plate and separate the face from the back. Buy tach pull the tach out of the bezel, pull the pointer off and unscrew the 2 screws holding the faceplate on. Drill the center of the delete plate for the pointer shaft and 2 for the mounting screws. Then put the tach guts into the back of the delete plate then the face of the tach with the 2 screws then the pointer then the delete plate lense.
That's a terrible idea IMHO. You'll probably end up ruining a very expensive tachometer. There is no reason to do that. It will fit into the dash the way it is.
The one problem with just cutting a hole through everything is I have pointed lenses and I don't think it will look right.
There's no need to cut through the lens,..the tach will sit behind it,..you'll need a tach with a black low profile bezel,..this one appears to have both. Autometer had a "traditional" tach with a black thin bezel but I didn't see it,..https://www.summitracing.com/parts/atm-2699/ Chrome pen the center of the dial and one would be hard pressed to notice anything at a glance
Have you or anyone done this yet? I have the black n silver auto meter. Or how good are the new reproductive taxes? Work with msd? Racing?
I have had this Autometer Tachometer in my dash for 10+ years. I mounted it in a clock housing so that it bolts to the back of the dash like stock. Did the same thing for Bruno. http://v8buick.com/index.php?threads/finally-took-er-for-a-ride.339221/page-7
Another version (link attached). Be neat if a guy could swap faceplates over but it looked a pile of work and might wreck the real tach, which I am not willing to risk. Had it repaired by a board member and back to stock, works good, but this setup worked out great and was super easy to do. http://fixjet.ca/tach.html
