Yes you are right. Someone converted to regular electronic ignition. Sorry I didn't see it myself!

To answer an earlier question that is a factory ignition box or maybe an aftermarket replacement for one. If it is good (and being as how you can start the engine it is probably good. But I didn't see a vacuum advance pod on the distributor whoever converted it only did 1/2 the job. Where is your timing set? With the lean burn distributor it can't change timing. Maybe there too much or too little for starting? The original ignition (on that truck) would have been either hanging off the air cleaner housing or in the fender behind the battery. Someone has halfway converted it to the much better earlier ignition. I wouldn't go back.
But you need to go the rest of the way. I'd get that done and then look into the insulator that was mentioned.
On
The fuel pump question look good at the block where it mounts. The shape of the flange in the block and the pump is not symmetrical. Look and see if the block and fuel pump flange meet up, should be able to answer that question for yourself.

Using factoty parts book for illustration purposes. Your full pump looks fine to me. There are three metal lines going to fuel tank. Fuel supply line 5/16 the big one, fuel return line 3/16 small with 1/4 hose fitting at ends and vapor canister to tank roll over vent valve. Roll overr valve is plastic one hose connection 1/4 it will break no replacement available.

Sending unit 5/16 the big one fuel supply, 1/4 small fuel return line , Both are steel

No I do not

They don't sell sending units? For this make and model?

Any sites for links for those carb spacers I couldn't seem to find any.

Not to sure since I bought a rebuilt one from orylies.

I'm not sure, but if you got a rebuilt one for your truck, which had the lean burn one system on it originally, then it may not operate properly when the lean burn system has been removed.

If you do not have vacuum advance on the distributor the truck is going to perform poorly even after you get it running.

https://www.ebay.com/itm/334347146249

Jus sayin....

They used to. The truck is old enough that they are discontinued. You may find one on eBay or a good used one from a boneyard. There used to be a couple of places that rebuilt them if you sent yours in. There is a company that reproduces them but many haven't had good luck with them. My son for instance has bought 2 of the recent aftermarket ones. One for an 80 D150 and one for an 89 ramcharger. On both of those the gauge does go to full when the tank is, like it is supposed to. But when they show flat empty both still have 1/2 tank, as proven by how much can be put in when filled up. I don't mind a gauge that shows a little lower than actual amount left, but a 1/2 a tank lead time is a bit excessive.
I'd rather find a Good used original or send one in to be rebuilt/reconditioned before buying a new aftermarket.