8 3/4 Sure Grip ratio change
I second this.
All changing the rear gear will do is change what MPH you change gear at. Not what RPM. 727's came from the factory setup for that car. The governor/linkage/line pressure in them was setup to change gears at certain MPH. Here is the factory chart:
Obviously with some cars having a higher or lower gear set, they would need to change at different RPM's in order to change at the same MPH. You probably just have a transmission that was setup with a high gearset (2.71 or something) so it shifted at LOWER RPM which was HIGHER MPH than you have now. If you need to up your full throttle shift point. Then you need to:
Check line pressure
Check shift linkage/kickdown linkage/throttle linkage
Change governor
Low line pressure or incorrectly set linkage can cause the transmission to "short shift" at full throttle. So make sure those are good first. If that is all set properly. Then you need to change out the governor. Check - Home - A&A Transmissions. They sell governors for 727s that will help you pick what it shifts at. BUT please MAKE SURE that line pressure/linkage is set properly before. Low line pressure is a main reason for low RPM shifts in 727's. And it will COOK your transmission if you aren't careful. Here's an article that goes a little more into detail. Increasing Shift Speeds On The 727 Torqueflite - Mopar Muscle Magazine
And no. Changing the torque converter won't increase WOT shift RPM. A shift kit, or new valve body might, but only because they are increasing the line pressure.
I second this.
All changing the rear gear will do is change what MPH you change gear at. Not what RPM. 727's came from the factory setup for that car. The governor/linkage/line pressure in them was setup to change gears at certain MPH. Here is the factory chart:
Obviously with some cars having a higher or lower gear set, they would need to change at different RPM's in order to change at the same MPH. You probably just have a transmission that was setup with a high gearset (2.71 or something) so it shifted at LOWER RPM which was HIGHER MPH than you have now. If you need to up your full throttle shift point. Then you need to:
Check line pressure
Check shift linkage/kickdown linkage/throttle linkage
Change governor
Low line pressure or incorrectly set linkage can cause the transmission to "short shift" at full throttle. So make sure those are good first. If that is all set properly. Then you need to change out the governor. Check - Home - A&A Transmissions. They sell governors for 727s that will help you pick what it shifts at. BUT please MAKE SURE that line pressure/linkage is set properly before. Low line pressure is a main reason for low RPM shifts in 727's. And it will COOK your transmission if you aren't careful. Here's an article that goes a little more into detail. Increasing Shift Speeds On The 727 Torqueflite - Mopar Muscle Magazine
And no. Changing the torque converter won't increase WOT shift RPM. A shift kit, or new valve body might, but only because they are increasing the line pressure.
