These engine tend to use oil because of valve stem seals. Both of my cars used a quart every 700 to 1k miles. I replaced the valve stem selas and the consumption went to zero in both cases. They also needed front main seals as well but the majority of the consumption was thru the valve stem seals.
I would recomend changing the valve stem seals and then checking your consumption. Valve stems are not very expensive. At your mileage its doubtful that the heads need to be reqworked.
I got too many cars!! Insurance eats me alive. Dave
78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k