I know I am jumping in before the OP, but just in case...
Assuming he got the kit from American Powertrain (don't remember for sure), looks like it is G3 and SB.
[URL]https://americanpowertrain.com...sing-for-tremec-gm-viper-magnum-t-56-6-speed/[/URL]
Here's the one that came in my SST kit:
[URL]https://threepedals.com/produc...-mopar-hemi-to-tremec-magnum-t56-bellhousing/[/URL]
I would bet there is only one manufacturer for the cast aluminum T56 bellhousing and all the kits come with the same one I have.