What tools and books are needed to rebuild a B&S push mower engine?

[sgkent]

Having considered the math of rebuilding older 4 - 5 HP engines, as others have said, it is less expensive just to buy a replacement. I recently replaced a head gasket and carb on a 20 year old engine, spark plug, air filter, adjust the valves, clean up and paint, and maybe had $85 in it when done*. I can't imagine adding a new rod, maybe piston, rings, gaskets and crankshaft etc.. It would be more than a new engine. These aren't collectors items unless one means the bone yard out back kinda thing.

* and that is a gamble because if the pressure washer pump on it fails it isn't worth throwing another $180 at it.