Manual Transmission - New Problem after rebuilding T56 (IDEAS?)

I recently finished rebuilding my t56. I was having difficulty changing into third and fourth gears. I found all fork pads to be worn so I replaced them along with the 1-2, and 3-4 synchros along with a steel 3-4 fork. I reassembled the tranny and went through all of the gears testing them before reinstalling it. Now I have a problem going into 1st and 2nd gears. When the car is parked I can put it in any gear I wish but after coming out of reverse or when downshifting sometimes it seems to lockout both gears. Anyone ever had a similar problem or have any ideas.

Did you line the blocker rings up with the keys on the syncro assemblies?

I think I did but i really dont remember. The car had been sitting on jackstands for so long I was ready to drive again and I may have overlooked it being in a hurry.

I'd say it's either something to do with your blocker rings or your shifter rails

Did you line the blocker rings up with the keys on the syncro assemblies?

X2 on this.