None of them that I used did I raced them from pre mid year 1969 model years though
I worked for the local telephone company back then and I would remove the magnets from the bad ringers, usually the coils would go open, and epoxy them into the drain plugs
I've seen some of the later aluminum case O.D. 4 speed tranny with a magnet fastened, glued, inside the cases on the bottom also
OP, if your dealing with a stock cast steel case slide it in near the drain plug and use it that way