Do what AK dieseldriver said.
Remove and examine that camshaft very closely. I see rust on it- hopefully that all just wipes off and is “spilled” from somewhere else. Knock the cam bearings out, remove the oil plugs everywhere and flush them all. You will need to do it again just before assembly, but expect to get our rust this first time.
Clean the cylinder walls, especially 7&8 and post pics of each. We can’t see the critical area near the deck surface in those pictures.
how much $$ you want to spend makes decisions on crankshaft, rods, pistons, wristpins, rings, and balancing. Best option is going to be p400 parts. Your call if worth the $. If I had gobs of money to spend, I would run p400 rods and pistons in a heartbeat, and a scat crank
You need to have cylinder checked to make sure they don’t need bored out because of rust, pitting, scratches before you buy pistons. And obviously have to but the pistons and rings before having it all balanced. Buying pistons and having it balanced to later find out the block needs bored and those pistons are not going to work—ouch.
Do you know how to file rings to gap them properly? My suggestion is total seal gapless rings. With gaps at 3/5 th to 4/5th loose end of the specification because the gapless will keep it sealed well, yet leave collapsing room for overheating error space since you are not going for big power, but long life.
Because you are ordering new parts and possibly the best ones-then having machine work done to them- I would expect payment up front to them. This is special order items at their most expensive.
I suggest you contact Chris
@Twisted Steel Performance for this, as he can buy the components direct from GEP/ AM General and is working with machine shops that have solid experience in this.
