!972 GMC k1500

[CRUSH2.0]

Hello everyone,
Well, I did it, I bought a 1972 GMC K1500 from Montana. Green and white mostly original paint with no rust and nice patina. I have a few questions:

Where do you find details on what a stock truck like this would have in terms of numbers, original interior pics etc,? Want to figure out what I have in terms of original pieces

I would like to keep the truck as is with 2 exceptions:

What is best way to improve steering and ride? Steering box, springs, shocks, lifts?
The motor is not original SB and very underpowered. Thinking about a new motor wondered if any of you have put in modern NA small blocks from chevy performance ?
Open to any other ideas to make the truck better. As I said not restoring it just a few improvements...maybe a killer stereo?!

Thanks