I have the oil pump all cleaned and ready to install on my C4 tranny yesterday. I placed the gskt. on the surface to check it and noticed that one part of the gskt. covers the large curved rectangular opening on the pump, all the other openings on the oil pump have openings on the gskt. surface. I called my tranny supplier and asked him about this and he says that there is only one oil pump gskt. for C4 trannies from like 1970 to 1981. Is this right? I have a section of a Ford service manual detailing the C4 tranny dis/reassembly and it shows a picture of the oil pump with the gskt looking like the one I have in my rebuilt kit. Does anyone know if that large rectangular opening is supposed to be covered up by the gskt.? Need to know please. Thanks.