Axle 8 3/4 end play adjustment

I didnt know the spacer was different on an open compared to a SG. I know back in 64 the open used a different thrust block than the SG (+.250) then it was the same for the 741/42/489 series starting in 65 regardless. read this and see if it makes sense:

"There was a difference in thrust blocks prior to 1964 that make center section interchange, as well as axle interchange problematic. The thrust block, or “axle shaft thrust spacer”, it thr block that both left and right axles butt up against inside the center of the differential. Prior to 1964, all open differentials used a thrust block was approximately 1/8″ to 1/4″ thicker than units made after 1964. The Sure Grip thrust block prior to 1964, however, was indentical to all 1964 and later Sure Grips and open differentials. In 1964, the thrust block width was changed to match the Sure Grip thrust block width..." sounds like they are all the same after 64?

I learned that you tighten the adjuster until 0 play, whack the axle in with a mallet. turn the axles a few times, tighten the adjuster again until 0, then back out to just a hint of movement, like a papers width.