One of GM engine looks like that, this is a pushrod engine, but OHC engine can produce more speed, power and more direct usually. Newer overhead camshaft engine with hydraulic lifter, which is self-adjusting and quiet than solid lifter and tappet, OHC engine no need to adjust valve clearance, so it’s more economic for maintenance and better performance usually.
Personally, I don’t like that engine.
This picture is really great though.