Transmission problems?

[1970 C10 MJW]

I have my swap done waiting to finish tune. But its driveable . anyways tuner never touched trans shift points but it shift manually fine. But in drive it shifts way too early. Suggestions?

[68c10airstream]

After sending out my pcm and then driving it afterwords the key item to remove is called "torque management". I had a free reburn and used it again to firm up the 1-2 shift and he took it as far as he felt comfortable with it and said i had to have a shift kit installed with a corvette servo, and have the servo pin fit for the trans (i believe there are 3 possible lengths). I sent it to a very good local trans shop for the install of above items and now chirp the tires on 1-2 shift during aggressive driving.

If i was to do any more to the trans software i would move the lock-up engagement point higher, from the stock 37 mph to say 45mph. This is on my 4l65e behind a mild 5.3

[clinebarger]

Originally Posted by 1970 C10 MJW

I have my swap done waiting to finish tune. But its driveable . anyways tuner never touched trans shift points but it shift manually fine. But in drive it shifts way too early. Suggestions?

Was the correct tire height & Gear ratio flashed into the PCM? Most of the time the shift points have to be changed to get it just right.

[68c10airstream]

clinebarger's answer is more to the point. I threw in my 2 cents worth for the sake of details for the software tuning aspects, good luck