67-68 T-5 shifter hole??????

i cut my 67 only a tinny bit just to make it easier to get to the bolts that mount the shifter to the tranny. you really dont need to cut it, but it makes the install of the shifter a little easier. i think i did about 1/2" onn just the passenger side of the hole.
 
I know you're anxious to do the job right and cut now but I'd wait until you can test fit it. You may not have to cut at all. I find if any cutting is needed, it seems to be needed on the passenger side and the front of the hole. Maybe a 1/4" or so, and still keeping the four threaded holes for the boot mounting.
 
Good advice above - the trimming (if required) will also vary depending on which shifter you use - some have larger collars than others...

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