u/0-0_0w0

I recently like last month bought this 03 2500hd with the gas 6.0 with 198k, had it inspected found "possible rear main leak" but nothing actively leaking, shocks are recently redone, runs m beautifuly for almost 200k a bit of smoke after starting up but goes away after driving for about a minute. Just want ideas on what to throw at it next. Currently just need to do tires wheels and breaks. Any thoughts or pointers?