- Rear gears would be fairly easy for anyone who knew their stuff.
- Read the casting numbers off of the heads (under the valve covers) and off the side of the block and from the intake manifold, and the serial number from the pad on the block to see if the numbers all hang together as being a complete, original engine. If so, at least one can then make a decent guess at what is inside there. (You can do all of this part yourself BTW.)
- Transmission type (904 or 727)
- Pull the protection plate off the lower end of the bell housing and look inside to see if the torque converter looks stock or is an obvious replacement
- Carb model number (the 'list number' since that is a Holley that you show)
- Ignition system type (OEM Mopar electronic or what?)
- Any obvious external engine mods like headers, intake, carb, and distributor. If these are there, get as good info on these parts as is possible. Take clear pix too.
- Take compression readings carefully on all 8 cylinders and list them here. As well as your altitude. This may or may not be useful, but at least you will know if the cylinder pressures are fairly even; if not, then more work is indicated.
- If the engine appears to be non-original (with non-original head castings for example), then it is almost a pure wild guess as to what is inside.