98 Ford Explorer-Blown Head gasket

My parents 98 Ford explorer was a fantastic car, giving almost no problems until I bought it. Now it has a “blown head gasket” My mechanic in Albuquerque tells me that the engine ( a 6 with overhead cams) tends to blow the head gasket after 80,000 miles, and that a rebuild will cost approximately $4,500. They say that simply replacing the head gasket isn’t a good idea as it when the head gasket blows a lot of other damage usually occurs. Could we replace the engine with a rebuilt V-8 that wouldn’t have this design flaw. Do you have any other suggestions? Particulars on the Car are: 98 Ford explorer SUV, 6 cylinder overhead cam engine, 4 wheel drive transmission, 88,000 miles, well maintained, usually with synthetic oil, interior and exterior in very good shape