# Muncie 4 speed question



## greenjudge69 (Mar 8, 2015)

On a 69 judge with an M 21 trans,. What are the correct casting numbers for the main housing,. Tailshaft housing,. And side cover? Also, should it have the bolt on,. Or stud and nut style of mounting for the linkage levers? I believe the speedometer hookup should be on the driver side of the tailshaft housing. Thank you.


----------



## integrity6987 (May 10, 2017)

recommend you buy GTOAA id guide by Eric White. From that book can get some answers:
M-21 from 1969 should have FT ide code and be mated with 3.90:1 or 4.33:1 diff.


----------



## greenjudge69 (Mar 8, 2015)

Thanks for your assistance. My car has it's original rear with the 3.90 gears still in there.


----------

