After cam break in

Ok guys, I broke in the new cam along with the Trick Flow heads on my 360la. I removed the inner valve springs for break in and everything went well. Did 25 minutes of 2400-3100 rpms and had 70lbs of oil pressure and temp was a solid 195. Moving forward I installed the inner springs and I used compressed air to hold the valves up. After finishing up I turned the crank by hand with the plugs out to check the rockers but I came to a hard stop. Engine will not budge. I backed it up and again came to a stop. Any ideas??