I've asked them to calibrate the compression tester on a known good engine and reinspect the rockers and push rods.
Checking ignition timing is a bit of a problem. Having an automatic trans means the flywheel is gone. When I rebuilt the engine, I filed a notch in the damper pulley that lines up with a stamping on the front cover at TDC for assembly and setup on the stand. Once the engine was in the truck it is very difficult to see. I set the distributor timing by vacuum .
