I just bought a 88 Samurai that I am wanting to restore and clean up. It is pretty close to stock, outside of a Toyota carb and missing soft top, missing A/C (is that normal for an 88?). The drive train/engine components all seem really good (was owned by a mechanic previously). I was told it doesn't use oil, but I did notice some oil on the front underside of the engine.

What are some basic first things I should look into doing? I am already planning on changing engine oil, radiator fluid, spark plugs, and air filter. Possibly changing transfer case and differential oil later.

Missing A/C or no A/C?  What's the difference?  If it's missing there will be evidence that it was originally there - part of the system still in place, holes in the firewall where the lines originally went through, that sort of thing.  I could be wrong, but, I think that the norm was for the Samurai to be shipped without A/C and if the purchaser wanted it, the dealer would install at the time of purchase.

Regarding the apparent oil leak/not using oil - wash & degrease the area and monitor, also keep an eye on the oil level on the dipstick - one of my vehicles has a leaking rear main seal, as evidenced by the oil on the underside, but there is no discernible change in level on the dipstick in 3000 miles, so I could realistically claim it's not using oil - given the work involved to replace that seal, it's unlikely to get fixed any time soon - on the other hand, if the rate of loss were to increase (or if the vehicle had a clutch that might get contaminated) I would approach the matter differently.

If the oil leak is one of the seals in front, have it attended to sooner rather than later as it will contaminate the timing belt and destroy it, if you don't know the change history of the belt, fit a new one whilst you're in there - the G13 engine is non-interference, so the worst case scenario if the belt fails is you'll be stranded on the side of the road (ask me how I know this  )

Other than that your proposed plan of action is sound - include the transmission fluid in your list of things, along with an inspection of the brake pad/linings and change of brake fluid.

Missing A/C or no A/C?  What's the difference?  If it's missing there will be evidence that it was originally there - part of the system still in place, holes in the firewall where the lines originally went through, that sort of thing.  I could be wrong, but, I think that the norm was for the Samurai to be shipped without A/C and if the purchaser wanted it, the dealer would install at the time of purchase.

Regarding the apparent oil leak/not using oil - wash & degrease the area and monitor, also keep an eye on the oil level on the dipstick - one of my vehicles has a leaking rear main seal, as evidenced by the oil on the underside, but there is no discernible change in level on the dipstick in 3000 miles, so I could realistically claim it's not using oil - given the work involved to replace that seal, it's unlikely to get fixed any time soon - on the other hand, if the rate of loss were to increase (or if the vehicle had a clutch that might get contaminated) I would approach the matter differently.

If the oil leak is one of the seals in front, have it attended to sooner rather than later as it will contaminate the timing belt and destroy it, if you don't know the change history of the belt, fit a new one whilst you're in there - the G13 engine is non-interference, so the worst case scenario if the belt fails is you'll be stranded on the side of the road (ask me how I know this  )

Other than that your proposed plan of action is sound - include the transmission fluid in your list of things, along with an inspection of the brake pad/linings and change of brake fluid.

Yeah I have heard of other older vehicles would get A/C as a dealer option. It has the pulley slot to run one, but I don't know that it means it came with one. When I get it home, I can investigate more.

Good call on degreasing and seeing what shows up. I was planning on cleaning up the engine bay anyway to check hoses that might need replaced.

If it has the double row crank pulley, then it likely had AC at some point. I have removed AC from samurais before and put all the non-AC parts in place (single row crank pulley, plugs in the firewall holes, replace climate control faceplate, etc. so no one would have ever known it originally came with AC by looking at it.

An oil leak at the front of the engine is likely the crank and/or cam seal leaking. Pretty common on samurais and trackicks in my experience. You'll have to pull the timing belt cover to try to determine which is leaking. Note, if you are replacing the front crank seal, you have to pull the large center bolt to get the lower timing belt cog off, so you can replace the crank seal. Be sure to torque the large bolt to spec. There are lots of threads all over the internet on what the proper torque is...I don't recall exactly what the spec is, but I want to say it is 94 ft.lbs.

I'd also change the spark plug wires, distributor cap and rotor, and fuel filter. The timing belt, as fordem mentioned, would also be on my list.

If the tcase, transmission and differential oil looks clean, then I probably wouldn't change it. But that's your call.