Join Date: Nov 2009
Location: Frum Hear Two Their Eventually
all 65-67 mustangs came with the C5########### cast in the side of the main case. this case has a treaded hole and screw that holds the top detent spring in. the 64-65 uses a "hatchet head" rail assymbly. in 66 ford went to a different rail kit. in 68 the casting number became C8######## on the side of the main case. the tag on the side tells what car , engine combo and gear ratio it "came from the factory" as. a lot of guys like me have made wide ratio close ratios and visa versa and left the tag on when we sold the car or toploader. its best to put the trans in 1st gear, mark the input , mark the output and turn the output shaft 1 full turn. if the input turns 2-1/3 turns its a close ratio , 2-3/4 turns its a wide ratio. all factory big inputs were close ratio only BUT theres some aftermarket wide ratio big inputs that look just like the factory close input. remember your dealing with transmissions 45 years old and no telling what some guy like me changed inside. btw , i only use the C5 main case and i use 4 hatchet heads in the shift rails instead of 2. the easiest shifting are the 66-up rails with round oval head detents.
Last edited by supershifter2; 08-21-2012 at 04:22 AM.