you asked : 'shifter hole' in my 69 Nova for my T 5 5speed shifter.
everyone likes "Pictures ........ pictures are golden"
#1 .. mark under floor for cut lines
#2 .. I did not 'remove my front seat or floor-mat ... just cut right through the floor mat.
#3 .. DO - NOT make your "hole too big" . I used my 'boot trim ring'
#4 .. I even made my hole smaller than I had marked .. worked good.
#5 .. you can see where I had the 1st holes drilled .... I drilled new holes closer together (smaller) -- I used my 'metal nibbler' and cut between those holes
RED dots were 1st marks.
#6
I like pictures --- I hope this helps .