That would be the best. Go thru the cooling system. Rad,water pump, all hoses and belts.
Next the fuel system as stated above. Same with transmission fluid,filter service.
Unless I am mistaken a 88 may even have a timing chain tensioner.
They greatly improved the gears and may not have a factor at 160K. Unless the van didn't see good maintenance over the years. Regardless anything can break at any time.If such van is in overall good shape,dive and enjoy.