Jeff's 727 rebuild thread
I did a bit of research and spent some time emailing very knowledgeable and friendly Pat Blais (Torqueflite Patty) about this subject and here's what I found out from him:
A "simple" part throttle kickdown feature was introduced on Slant 6 904 transmissions in 1967 and forward and it remained the simple kind in slant 6 904s.
The "complex" part throttle kick down feature was introduced in 1971 in low performance V8 727 transmissions.
The difference between the simple and complex part throttle kickdown feature is that the complex is more sensitive to throttle position offering the 3-2 kickdown at appox 3/4 throttle where the simple kickdown 3-2 feature occurs at around 7/8 of full throttle.
The simple part throttle kickdown from the slant 6 904 will bolt up to the '67-'70 727 valve body, but not bolt up to the '71 and up 727 complex valve body. The simple part throttle kickdown will however bolt up to the 1971 and up 904 transmissions with the 4 screw top cover.
The complex '71 and up style will bolt up to the '67-'70 727 valve body.
I'm adding a complex kickdown package to my '70 727 with 2.76 highway gears so I don't have to mash the throttle to the floor to get the car moving on an on-ramp.
I hope this info helps somebody else out.
Thanks to Torqueflight Patty for all the info, all the time spent, and pictures to explain these details.
"Simple" part throttle kick down
"complex" part throttle kickdown
I did a bit of research and spent some time emailing very knowledgeable and friendly Pat Blais (Torqueflite Patty) about this subject and here's what I found out from him:
A "simple" part throttle kickdown feature was introduced on Slant 6 904 transmissions in 1967 and forward and it remained the simple kind in slant 6 904s.
The "complex" part throttle kick down feature was introduced in 1971 in low performance V8 727 transmissions.
The difference between the simple and complex part throttle kickdown feature is that the complex is more sensitive to throttle position offering the 3-2 kickdown at appox 3/4 throttle where the simple kickdown 3-2 feature occurs at around 7/8 of full throttle.
The simple part throttle kickdown from the slant 6 904 will bolt up to the '67-'70 727 valve body, but not bolt up to the '71 and up 727 complex valve body. The simple part throttle kickdown will however bolt up to the 1971 and up 904 transmissions with the 4 screw top cover.
The complex '71 and up style will bolt up to the '67-'70 727 valve body.
I'm adding a complex kickdown package to my '70 727 with 2.76 highway gears so I don't have to mash the throttle to the floor to get the car moving on an on-ramp.
I hope this info helps somebody else out.
Thanks to Torqueflight Patty for all the info, all the time spent, and pictures to explain these details.
"Simple" part throttle kick down
"complex" part throttle kickdown