New to Dodge trucks.

I started my mechanical life with Fords, I had a number of Torino's and LTD's.

AFter getting tired of tracking down Ford one year specific parts I got involved in Chevy's, K5's, C10's and Suburbans.

My daily driver is a F150, I really don't play the Ford/Chevy/Dodge popularity game, they've all got their positives and negatives.

So my new project is a 1991 D350 that my father-in-law is passing on to me.
It hasn't been run for a few years and not on the road since 2009. I know cars/trucks, just have no clue about Dodge, something new and exciting!

My father-in-law bought this 1991 D350 out of Yakima, WA back around 1998 and used it for his drywall business in Salem, OR. He retired around 2008 and it hasn't been used since. Likely has fuel in it from 2009.

I don't know squat about Dodge trucks but since I've recently built a little urban farm I could use a big truck to haul some larger items around.

Here are some specs I know, they may or may not be important or universal...
1991 D350 159"WB DRW
12' x 8' steel flatbed
Interior is pretty sparse, rubber mat, vinyl bench seat, droopy headliner
4,000 lb front axle (option?)
5.9L holley throttle body
auto trans, options say standard
Rear ratio 4.10







Should be pretty simple, but couple of questions to get me started...
What are the better brands or OE for things like plugs, connectors, fuel pumps, etc. I don't want to buy off brand, sometimes OE is worth the extra money.

What are the items that are easy upgrades? Or common broken parts?

Best shop manuals?

Thanks for any help or information!