Ohhh, burning oil bad. This sounds like he didn't take great care of it possibly and you may be in for some repairs pretty soon. If it mostly smokes when started and then stops...it probably is the head sucking oil thru the valve guides or oil seals on the valve stems. Those valve stem seals are an easy fix, just time consuming. If it smokes when you hit the accelerator, it is rings. Now that you say it burns oil, the noise is probably a symptoms of it's age or abuse.
If you have a compression gauge, you may run a test to see if it is one or all the pistons that show bad testing. This also will give you an idea how bad it really is. It could have good compression, but drinks oil which can determine bad oil rings on the pistons. Valves stem oil seals can prevent a large amount of oil from getting into the combustion chambers, they are usually what goes sooner then other items.

These motors can last anywhere from 200K to 400k before a rebuild, if taken care of. Mine went 275k before I had to go through it and it really wasn't too bad except for piston slap and a quick loss of compression.