This is a Ford water pump, the pulley is for a 6 blade fan with bolt size of 8M x 20 if your pulley is different please call for correct pulley, for if wrong you must pay shipping of correct pump. also some Shibaura from 11/74 to 79 the tractor is a Ford 1000 and 1600, It has been re manufacture with new bearing seal and impeller, also comes with mounting gasket. There is a $20.00 core charge that will be invoice with Pay Pal. This invoice will come from Pay Pal for E bay has no line for core charge. When I ship your pump the box will have a prepaid USPS address label to return your core just gave to any USPS driver, or drop off any post office. (as stated it is prepaid no fee to you.) & If paid by pay pal will credit your account if by check will mail you one back. 30 days warranty if any question on this pump or any pump please email. Thanks for your time. If you want to see a pump listed please email, or if you need other payment arrangement please email or call If out of rebuilt pumps will send new.