Depending on where you live and who does the work, retail price for a top end rebuild is about $3000 with labor and reman engines seem to run $3500-4500 before installation.
Folks with a modest knowledge of mechanics, physical ability and who can follow a manual can do the work themselves saving $1000+ in labor costs but broken exhaust bolts will need extracting and surely slow the process down.
The best way to check the lifters is first by sound and then by monitoring each cylinder's performance with a Tech2, GMs tool for working on these trucks. It can test the fuel system, ignition coils and AFM system and see where any problems lie. This I would do first to gain as much knowledge as possible as to what is exactly wrong with the truck.
If you decide on a reman or new crate engine, get the ones without VVT, that feature came out in 2010. Your engine is the all aluminum LC9, you can confirm that by looking for that on the RPO sheet on the inside of your glovebox door.
At 215K, it's time for a mid-life overhaul. If the front suspension and steering was not rebuilt it's likely time. same with the rear, all fluids should be changed every 50k or 100k miles depending on how y'all drive it.
If you do not desire the original fluid filled motor mounts which helped dampen engine vibrations, people use the mounts from the H2 Hummer. Not sure how that will affect the truck in V4 mode so you might ask around about that before deciding which way to go.
Post up where y'all live, there may be forum members close by with a Tech2 or good scan tools that would be delighted to help.
