My faithful 2014 Tahoe has an oil pan leak, a valve cover leak and a rear seal leak. Otherwise with 166,000 miles it runs great.
It would take me hours to fix my self because of all the stuff in the way of the valve covers and the oil pan that has to be removed. I look at my 76 Silverado and realize it would be an easy job. Simplicity rules!
Door 1. Get leaks fixed and hope to get another 25000 miles or more. Cost around $2500
Door 2. Buy a new or low mileage SUV or Truck for 45,000 to 70,000 with so much technology and crazy engineering that it will probably cause trouble in a year or so.
Door 3. Have the engine in my 76 Silverado rebuilt with a towing cam and about 340 hp. New heavy duty shocks etc. Around 15,000 to get in top shape as originally paint and upholstery are in good shape. At the end of the day I could easily work on it. It would have a chance to appreciate in value as opposed to watching $50,000 for a new one depreciate.