Can't turn the crank

You have over tightened your rocker arms and probably have a valve up against one of the pistons, As it sez on Autozone's instructions tighten the nut until the lash (play) is eliminated then tighten according to the instructions from Autozone below: 1994 Chevrolet Camaro This is from www.autozone.com website This is just the printed instructions and if you go to their site there's diagrams also to help you To install: 4. Coat the bearings surfaces with a thin coating of Molykote or its equivalent. 5. Install the pushrods and make sure the rod is in the lifter seat. 6. Install the rocker arm, balls and nut. Tighten the nut until all lash is eliminated. 7. The engine must be on the No. 1 firing position before proceeding. This may be determined by placing your fingers on the No. 1 rocker arms as the mark crankshaft damper is rotated towards the "0" on the timing tab. If the arms did not move, it is in the No. 1 firing position. If they did move, turn the crankshaft one full revolution to reach the No. 1 position. Remember, the mark on the crankshaft balancer must be aligned with the "0" on the timing tab. 8. Adjust the valves as follows: V6 ENGINES With the engine on the number 1 firing position, exhaust valves 1, 2 and 3 and intake valves 1, 5 and 6 may be adjusted. Back out the adjusting nut until lash is felt at the pushrod. Tighten the adjusting nut until all lash is removed, then tighten the nut an additional 1 1 / 2 turns to center the lifter plunger. Turn the engine one revolution until the "0" timing mark is once again aligned. Exhaust valves 4, 5 and 6 and intake valves 2, 3 and 4 may be adjusted.

is the belt off this might make it easier