My Jeep is a '91 Limted with a 4.0. The problem is it has 263,000 miles! It runs fine, but blows oil out the PCV. Has anyone seen this problem? Is the motor worth fixing and cheaply rebuilding (rings, main bearings) or should I replace it? I've found a '93 4.0 out of a Grand Cherokee that I can get for $200 with about 140,000 on it. Would everything be the same? All the sensors and wiring? Tight budget for the Jeep, being just a toy. Any advice would be appreciated.