98 GMC Suburban Revival

[Yukon6.2]

Hi All
I need a road trip vehicle for a spring road trip which will include visiting a friend that has a 100+ kilometer unmaintained driveway.
So i chose the diesel Suburban that had been left behind by the PO,with plans to retrieve at a later date.I had given him a pickup in trade,that he was supposed to return in similar shape.He passed away and his family did not want to retrieve the Suburban.
I did a quick assessment when i cleaned out a pickup load of cloths from it a couple years ago and got it running.
The cat was plugged solid,i removed it and it ran.Brakes were gone so i did not drive it much.
At the moment it needs complete brake job,alternator wasn't charging and running like crap.

So i am looking for ideas on the crap running part.

It's not throwing a code,but acting like it's still stuffed up.Lots of black smoke and no power.
To get it running a few years ago i had to wire in the lift pump,relocated the PMD from the intake to in front of the left battery behind a hole in the rad support.
Online last night got me a price of $1600.00 for master cyl,rear shoes,drums wheel cyl,seals,hardware,front rotors,pads,calipers and alternator.Delivery March 4th.Going to see what prices are like with my account local.
I hope to get a few weeks driving before the road trip.
Interior needs to come out for a good cleaning.
Thanks for any insite and advice as i move forward.
Thomas98 sub.jpg