A puff of exhaust smoke on acceleration from a stationary start might indicate worn valve stem seals. #1 cause of exhaust smoke and oil burning/consumption in these engines. Gen 2 trucks 'should' have hydraulic heads, but you never know what a PO has done to get an engine running. If it's apparent the valve stem seals are shot, it's a good a time as any to scrape the crap off the pistons and send the head off for a hot tank and reconditioning...