1972camarols1

I have a 1972 camaro with a LS1 with a 4l60e trans. The 4l60 is new. It had a 6 speed in it till i swapped to the 4l60. I purchased the pigtail that plugs into the PCM and the auto trans so I could use my same computer. I have it all hooked up and for some reason when I put it in drive it feels like it's in 2nd or 3rd gear. . I have hp tuners and it says that it's always in 1st gear, even when it's in reverse. But it's not in 1st gear. Reverse works perfect. Y does the computer always say it's in 1st gear even while I'm in reverse? Is this strictly a computer tuning deal? Can someone please help me with this?