You're welcome, Bill.
Somebody will have to tell you why the two different rear hoops for the same tranny. I suspect that the attachment is all that is different (i.e. when you use the top hoop with a 352, you have a mounting plate similar to a 365 and when you have the hoop with ears, it requires a different mount). Did you say you have a Spyder frame? If so or if you're doing a frame off, it would be a great time to choose an NG3. They are more current so parts are available and they are 5 speed.
This is all I was able to find about the 352 mounting plate. The one in the picture below looks like it would be used with the top hoop (that is also used for the 365). I don't know how it mounts to rear hoop with ears.