So what am I looking at exactly
Is there anything I can assume has been done to the engine without tearing it down.
- Read the head casting numbers cast on the top of the head where the runners are cast, and compare them to the year and block numbers.
- Take compression readings on all 8 cylinders and report them; those may or may not tell something about pistons
- Borrow a dial indicator and measure the peak lift on any one intake and anyone exhaust valve; this will tell you if the lift is different from the original cam lift
- Pull the rocker assembly off of one side and look down the pushrods holes at the tops of the lifters; if they are hydraulics, you will see wire clips or c-clips inside the tops of the pistons, around the socket where the pushrod sits; there retain the internal pistons . (You might even bee able to tell this by looking past a pushrod as they are but it may be tough to tell without removing the pushrod.....)
- Perhaps even borrow a borescope and look at the top of one piston through a spark plug hole
BTW, looking at the 3d spring in the 2nd pix, it almost looks like a 2nd spring is lurking in there; hard to tell. The OP should look inside the valve springs and tell us if he sees a smaller spring wrapped in the opposite direction, with small round spring wire