2013 GMC Sierra 3500 K3500

Description

2013 GMC 3500 HD, 4 door, cab and chassis truck with CM flatbed.
I purchased this truck with a rebuilt title in 2015 with only 43,000 miles on it. The drivers side door panel and top of steering wheel was damaged already. It had suffered from front drivers side quarter panel damage by the original buyer, the grill, hood and fender had all been replaced and the driver door had been straightened out and repaired.
If you pull a title report you will see when I bought it and then retitled it in a business name then put in back in my own name again.
I had the rear seat removed and door panels cut out to accommodate a DOT legal sleeper birth. I used it as a hotshot truck until 2019. Well kept general maintenance and a water pump, until the engine blew up in 2018. I had Frank Kent Country Chevrolet in Corsicana, TX put a new long block in at around 190,000 miles. It currently has about 240,000 miles on it. (I will update this number next time I'm at the shop and can double check.)
It currently runs and drives but it needs the following repairs.
-It is getting exhaust gas in the antifreeze which indicates a cracked head or a bad head gasket, I am inclined to think head gasket because it came about very slowly and took some time to actually diagnose. I've been using it on a limited basis to pull my skid steer around for work. I've watched the temperature close and it has never overheated although it pushes a lot of coolant out of the overflow bottle.
-Batteries are weak and if it sits for too long they don't have enough juice to start it. Doesn't start below freezing temperatures well anymore.
-If it sits too long the fuel seams to be bleeding off. "replace fuel filter" light comes on even after replacing the filter 100 miles ago.
-stopped burning DEF fluid. Factory exhaust components are still there but it just doesn't use fluid anymore. Tuner sells with the truck.
Has had the following repairs somewhat recently. New alternator, new ECM, rear seat and door panels reinstalled to functional state, although there's no speakers in the rear doors anymore.
This truck has served me well and I think with a little TLC has a lot of life left in it. It has dual fuel tanks and will hold about 60 gallons. The flatbed has one tool box on the driver side and a box on the passenger side.
I've been going to repair it and continue using it but I am too busy and my mechanic can't get to it for a year. It's in my way in the shop and my other truck is back, so down the road it goes.