inspecting main and rod bearings

[ktbtrucking]

thank you for all the replies, have a truck it is mine and I understand the engine is worn out with 1.2mil miles, do not have to drive it anywhere anmore and I am glad that it did not break down over the road so far, just have some time to assembly/dissasembly parts just for knowlegge how things work, have also started other thread http://rawze.com/forums/showthread.php?tid=2278,
dropped oil pan and dissasembled driver side of the engine to locate engine oil leak (just to kill some time with friends)
no work on bearings now( you need some good clearance under to do it with no stress I bet)

up to the point, put everything together with new oil , after start up blowby is really low , have not screwed rocker cover at all just covered, after around and hour of PTO idling have some really bad oil leak form rocker cover,
tightened rocker cover up and started an engine ( watched isx oil lubrication system on youtube to know how things work)

removed the oil fill cap and have some steady blowby there with some oil blowby from crankcase breather too ( if I compare to youtube videos it does not look bad with my engine) but looks like have some extensive pressure buildup under rocker cover because there is a lot of flow form oil drip channel located at the back driver side of an engine ( from a schematics it is oil drip channnel directly from head to oil pan) so i assume there is a lot of compression going from oil pan up to rockers area
Just would like to know how things work? Apologize for long post though .