If you can lock the crank down some way from turning, its a good idea to do a leakdown in a few spots to see if there is cylinder taper, wear, or bumps.
They showed us how to do that at a Cummins training seminar, the "test" engine had zero leakage at TDC, but had a bad leak when the piston was about half way up. On a cummins you can lock the flywheel anywhere with a special cogged tool that goes in the flywheel.
You just have to make sure your in the compression stroke when you test this or the valves will bleed off all the air ofcourse.
