<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: OneStopRestoration</div><div class="ubbcode-body">
I got the slider out and found out why. GM put an M21 slider with the locking groves for 4th gear in the M20 with High performance engine
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Are you saying this slider was normally only used with hi-perf close ratio M21/M22 transmissions? I thought the locking feature was relatively common on ALL Muncies from the era.