Cool Dave’s 1973 Dodge D100 Club Cab

I want to say it specified somewhere around that 5* mark but I will confirm. In terms of smog stuff it seems like it really only has the charcoal canister which has all the lines disconnected to/from it and that EGR valve.
The charcoal can may need some vacuum for purging.
Main concern functionally will be the fuel tank vents where ?
The carb in the photo has a bowl vent inside the air cleaner, so it will work fine. The charcoal can connection to the carb bowl is typically only for controlling bowl vapor when the engine is off. Nice but but not neccessory (and can be problematic).
The last point to note for future troubleshooting too, this motor is not original to the truck. I’m not sure what it came from but it was swapped in around ‘05-06.
Huge! So its an unknown mishmash of carb, distributor, and emissions stuff.
Block and intake may have casting dates you can see (with some effort).
1) Does the EGR need to be functioning or can I simply leave it capped?
I think the answer is: yes with no vacuum the valve will be closed at all times.
As far we know, it doesn't have the matching distributor so this is the simplest route.
Emissions delete is going to be the easiest route. EGR should be easy enough to hook up later on if you choose to.
If the heads are late enough, they will have air injection holes under the main exhaust ports. They will need to be plugged.
2) Heat riser valve on the passenger side exhaust.. how do I confirm it’s working correctly?
When its cold, see if you can rotate it by hand - it should move and then spring back. Nice but not super critical. Wire it open if/when it fails.

Going emissions delete, but mystery distributors, I'd start with timing around 5 to 7.5* BTDC without vac advance. Note the rpm!
Then measure timing at some other rpms. You will be limited to the timing range on the cover unless you have timing tape, dial back light, etc. Its super important to know the rpm of any timing measurement.