just put another transmission in my blazer, this one wont go into any gear, not engaging, is it something simple or did i just spend 500 on a piece of junk?

 

check your brake pedal it might have a small sensor that does not allow the vehicle to change gear without pressing on the brake.(child safety device)
had the same problem on a different vehicle

 

im sure its not that cuz reverse or any foward gears engage when going through the column

 

Can you feel the transmission shift into Reverse, or OD, D, 2, 1? Hopefully you know what I'm talking about. Your indicator on the dash shows the correct gear according to shifter location?

I keep this link bookmarked. Has helped me out once already. Troubleshooting is about 3/4 of the way down.
http://www.drivetrain.com/parts_cata...rhaul_kit.html

It takes a gallon just to fill the converter alone(which is why I never get enough in after a rebuild).
I fill until it starts showing up on the dipstick, then I put the drivewheels off the ground, start engine, put in gear, pull the dipstick, and listen to the tube. If I hear the pump sucking air I add more until it stops. This has happened to me twice already. I add what I think should be the correct amount and it's not enough.

You don't need to put it up in the air, but the fluid level should be checked in gear anyway. I just put it up because I never have an assistant around to help.