A Body Aftermarket Tach Size

I've seen only 1 aftermarket tach installed in this panel. Was a dang mess too. The instrument housing and bezel were butchered, the adjust stems and such sticking out the back of the tach were crushed against the column support, its wiring was pinched and shorted.
Cleaning up that previous owners mess cost atleast twice what it cost to create the mess.
Year One, ebay, lots of places offer a tach that does fit like OEM.