727 experts? Need help

Hey guys,

Just got my engine done and put back in the rig, however I have no power to the rear wheels

Things I've done with trans
Add different torque converter (went in nice, rotated and felt it lock in)
Dropped pan and valve body to take out shift shaft. Was leaking so I had it machined down some and added a new seal where it comes up out of the trans.

When I put my shifter to park I can still roll the car?? Could I installed that shift linkage in the trans wrong?

No oil coming out rear trans line when I checked, But I'm not even sure I'm in neutral. I checked with my pen light on the neutral switch and it lights up. However it should light up when I'm in park too but it's not? And again when in so call park I can still roll the car.

I'm lost