Looking for Spark Plug Help

[Jason Bourne]

My son is looking to replace the spark plugs on his truck. Normally I'm a big believer in replacing with OEM. The problem is the engine in my sons truck isn't OEM. The truck originally had a 350. At some point the engine was replaced with a 283 that possibly was bored out to 305. It has a 4 barrel Edelbrock carburetor, headers, and sounds like it might have a mild cam. The 283 might have come out of a 1964 Chevy II.

It currently has R44T spark plugs installed. Don't know much about distributors but the one installed is labeled Delco Remy. It doesn't have a coil wire leading to a coil like I have seen on other engines. It has a block on top that I assume is some type of electronics maybe? I'm attaching a pic of the distributor.

Can anyone give a recommendation on a good spark plug replacement? Should we just replace them with new R44T's? Is there something better available? What should the spark plug gap be set at? Also looking to see if new plugs can enhance the trucks performance. Currently it sounds like Tarzan but runs like Jane.

Any insight is appreciated.