I have a 74 Z28 with an M20 Muncie 4-spd and I'm missing my reverse lockout rod. My assembly manual has part #s 493453 and 3975618 as the correct rods. I've tried repro rods online, but they are all 20 1/2" long, whereas measuring my stock setup revelas that it should be 21 1/2" long. Anyone have any insight on this problem or know of anywhere I can get one that fits???