Measure the inside diameter and depth of the hole from the inside flat surface where you would start to slide the bushing in from, I hope that makes sense I have several crankshafts with stick shift bushing in them to look at and measure, usually the 383 crankshafts had a short pilot hole on the automatic cranks or the proper deep pilot hole for the bushing for the stick shift cranks Not like the 440 cranks that had a deeper hole and a smaller diameter on some of the automatic and the proper depth and I.D. on the stick crankshafts