Can you use a 4l60e in an older motor and car?

Yes you can, but you'll need the TCM and harness to match the trans. There is no governor in the 4L60 so it relies on inputs from the speed sensors to manage shifts. You'd be better off finding a 700R4. They're cheaper, easier to find, and ratiOS are the same as the 4L60. It's even got lockup converter provisions.