200R4 update
I called two places that sell the TCI small block mopar spacer/adapter, they all said 1/4" aluminum. It looked thicker than that in the pics that "Mopar to ya" posted. It's really important because the thinner the spacer the less you have to cut out of the upper trans cross member.
It would be nice if Mopar to ya checked his (or anyone else who has used the TCI) for the exact dimension. I'm going with the TCI simply because the others are thicker. When I mocked-up my 200R4 I used a 1/4" spacer to get the trans mount dimensions from the trans face. If it's not 1/4" then I need to know fast!!
As you can see in these pics...I'm mocking it up right now.
Treblig