727 not shiftin to 2nd or drive

A few possibilities exist.

1. Is it full on fluid? If not fill it and test drive it again.

2. Since it's a rebuilt trans. it's possible they put a valve in backwards in the valve body when they assembled it.

3. Also possible is the governor or a shift valve in the VB is sticking cause it sat so long and got a little rust on it.

Try installing a can of K&W Trans-X that you can buy at Autozone for about $8. I've had it free up stuck valves before and never had a problem again. If it does nothing for it inspect the valve body to see if everything's put together right and all the valves work freely. If that still don't fix it check the governor for problems.

BTW: Was a shift kit installed?