Well, if it's not running, or was smoking like a big dog, just pull the head off......it ain't gonna fix itself.
But I digress............
I use a cyl leakdown tester, but you can check it with just an air blowgun.
Pull the valve cover.
Bring the piston up TDC on compression stroke, hold the flywheel/crank securely( however you wanna do it) and push a little air in the spark plug hole, and listen for air in the pushrod galley and/or all around the outside of the head.
The Slapper, AKA Mr. Kohler, might be able to offer up some ideas...........
It ain't rocket science!
'Course if yer house has more wheels than yer truck...
" Old age ain't for sissies "