Hi Wendell, I'm glad to assist you. As per checking, DNJ does not mention the piston size anymore since this is has the factory standard size and not for an oversized cylinder hole. The important detail to check, as noted on the fitment information, is the required VIN number 2 to check for the 1500 models and VIN letter D for the 2500 models for the 2007 Dodge Rams with 5.7L engine size. Once checked and confirmed you have those corresponding VIN number or letter for your 1500 or 2500 Ram, this is a guaranteed fit. Please click the link below to order this part later on and take advantage of our ongoing promo sale price for this part. I hope this helps. Happy shopping. https://www.carparts.com/piston/dnj/dnjp116140?can=CPJE1043