904 slow 2-3 shift, should I be worried?

Question, there's a section in the TF-2 instructions that says to drill 2 holes in the valve body where the lockup valve is if it's a 1977 or later unit. Mine is a 1977 but it's non-lockup, it has the valve in there but it's held in place by a spring and I assume does nothing. Do I still need to drill the holes or can I leave it alone?