1990 f350 custom 7.3, new batteries, new alternator, starter, starter relay, grounds to Frame solid, turn key and get very weak radio/dash lights, start light goes off and attempt to start and all I hear is a clunk on the upper right side by where the starter relay is. lost without any further ideas, any assistance would be appreciated.

[ 2 weeks ago, This truck ran 5 hours no problem then died, that's when the above parts were replaced].

 

Did you check or replace the battery cables? Even though they may look good, the corrosion can grow under the insulation. You might want to double check that.
Also are the batteries fully charged? Sounds dumb, but just because they are new, doesn't mean they are fully charged.

 

^^^THIS^^^

Make sure you aren't using parts store cheapie battery terminals on your cables.

https://www.summitracing.com/parts/ado-3ba35

If the battery cables or terminals are damaged you should replace the battery cables. Here are some good suppliers.

https://custombatterycables.com/

https://www.batterycablesusa.com/

 

So tell us what you have for test equipment so we might be able to direct you down the correct path.

 

they are, I checked them prior, I've been checking wires, not seeing much I haven't seen prior, nothing to note. Just curious to the thump sound on starter solenoid side of engine. Tannerite is looking good!

 

From your discerption could be several things such as fusible link, poor connection, bad wire etc. You have thrown lots of parts at it with no results it would appear. I asked a question which hopefully would help get you started in the correct direction for repairs. Maybe you missed it so will ask it again. What do you have in the way of test equipment? Things such as a good digital volt meter, test light, induction amp meter to name a few. And maybe the most important tool the wiring diagrams for this application! Money well spent if you do not own and probably cost you less then what you have invested in parts so far.

Your clunk from starter relay sounds like low voltage which is verified by weak dash lights, radio etc. Could be some bad grounds or could be a supply side issue. Either way without some test equipment and running a couple of load test you will just be guessing as to the issue.