Check compression. Good compression + burning oil usually means bad valve stem seals. Your engine may only need to have the head off and a tidy up (you can eyeball the tops of the pistons and cylinder bores for overall condition - if the bores still look solid, bang some stock rings into it and give the bores a once over) Do the all of the belts, replace any suspicious seals and fit a good quality VRS kit when reinstalling the head.

*the oil burn from dead valve stem seals will drop the octane rating of your fuel - so you lose oil and horsepower at the same time.