Used Detroit Diesel heat exchanger coolant tank 5135271. For use with heat exchanger core 8509553 or 23520298. with a 6 3/4″ X 6″ mounting flange and 10 holes. Includes transmission gear oil cooler. Good condition. Removed from an 871 parts motor and has been in storage. Skippers Marine specializes in new old stock, recycled and those hard to find marine parts and accessories. Please check out my other Ebay store items. Don’t see what you are looking for? Feel free to send an email request. 6-0535