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lt1 4l60e swap need help

1219 Views 3 Replies 2 Participants Last post by  cahall
I swapped an LT1 and 4l60e out of a 97 Camaro into my 56 Chevy. It drives nice but the shifts don't feel correct. For one, the shifts aren't positive feeling at all when it shifts normally it almost pulls the car back than pushes it forward. It also seems like the shift process if very delayed. Again I am use to th350/th400 shifts so I don't know if I am to expect something different with this transmission. Also when it downshits it hits the rev limiter before the car start moving. I have the PCM shift points at a stock Impala settings. I have my speed scalars adjusted properly for my rear 3.70 rear gear. Any opinions?
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What year computer are you using? You have to use a '96-up for the downshifts to be correct. IHas the transmission ever been built or modified?

The computer and harness are 1995 OBD1 for ease of tuning. I am using the Impala shift parameters. It only has this problem shifting from 2>1, where it hits the limiter. My rev limiter is at the stock 5900, maybe it needs to be kicked up a little bit for the 3.70 rear gear since it revs a lot quicker? The transmission is a stock rebuild.
The '95 and '97 4L60E use 2 different downshift strategies. Your computer and transmission aren't compatible. In '96 GM changed the valve body, seperator plate, 3-2 solenoid and wiring harness. We get this same complaint all the time when people install later transmissions in 1995 vehicles.
The soft shifts are most likely just a result of a stock build.

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