Transmission problems
 

My son's 4runner blew a head gasket. I pulled the entire engine out and rebuilt it. I fingured that since I was in it, I minus well do everything. Now that the engine is back in and running, I went to put the truck in gear and nothing happens. I can put it in any gear, reverse, forward, etc. and it will not move. It is like it is in Neutral. I can roll the car but that is it. I'm wondering if I did something to the transmission when I put the engine in.

Thanks for you help.