Can't beat a forged Wiseco as a better replacement for the oem cast piston. Available in over sizes up to 2 mm over standard bore size. Just measure the cylinder to find what over size is needed to clean up the cylinder. Going too large really doesn't accomplish anything and takes away from the cylinder sleeve.Doesn't matter if it's an Express,Explorer,etc as all the engines and pistons are the same.wiseco Polaris 300 pistons | eBay
Plus the first 300 to come out was a 94 model,not a 93.