know of a source for misc. 4l30e internal parts?

about a month ago, i disassembled my 4l30e GM transmission to replace a gasket...long story short, i had to transport it about 100 miles in a semi-disassembled condition. there was one part from the oil pump that i KNEW i would lose, so i took exceptional care to put it up. either i've forgotten where i put it, or i've just lost it somewhere. the part in question is a little plastic restrictor, about the size of two peas stacked vertically. it fits into the body of the oil slinger in my transmission. my vehicle is not equipped with the oil pump (no gears in the body). afiak, it is not necessary for operation, but was put into lower weight 4l30e applications to delay shifts (the heavy ones like trooper/rodeo lack it). i'm thinking that i'll have to buya used pump off of someone to get a replacement, but would like to at least ask first. if not, anyone know the "number" or address that I could reach an appropriate person at hydramatic to order a replacement? thanks.

If it's something that would have also been in the 3spd try GM dealer, it was used in Chevettes and postal jeeps.