Hey, Thriftmaster, I read the desciption of your truck in the gallery. You mention that the engine has been changed. It could be possible that the rear has been changed as well. Does it still have the closed drive shaft, or is it open? If it's an open drive, then the rear has been changed, and may be a later 12 bolt differential. If you can post a picture of the housing and/or the cover, we may be able to ID it for you. The flaps should be able to match it up in their gasket catalog, most of them have pictures of the gasket shape with the listings.
Tiny, never heard the one about using kite string, sounds interesting. Have you used it yourself?
