[Transformula]

You're probably right on the adapter plate thing. I am familiar with the SAE#2 clutch housing which is round with 12 bolts. They are for a 14 inch clutch. Try this site: www.roadranger.com and go to the middle lower area where it says electronic parts catalog and see if anything might help, although I bet GM did make their own adapter. At least you can easily get anything else you need for the trans itself! Here in Amarillo, there's a truck junkyard with all big trucks, tractors, buses, etc, and I wonder if a place like that might have odd things like that...