I heard that the 8.1 was originally designed as a marine engine, has a super strong web casting, roller tappets and is almost like a diesel engine in torque, and some agency decided it was too good to have in the 2500-3500 series trucks and GM discontinued it, you can still get the engine from a 2 ton chassis or as its original design a marine engine or in an RV.
Talk on the streets is to keep the motor, years from now it will be the most sought after high performance big block platform short of a Rodek.
It has serious torque. I pull trees out of the ground in low gear at idle. It is a trip to see the horsepower and torque combination this thing has. On the highway, at 80 MPH it is running below 2000 RPM in 6th gear.