I'm looking for the best match to my bbk IM. Right now I only have a couple ls TBs. I guess the gsr throttle body is a little bigger, and then the type r is till bigger? The idea just occured to me that maybe I can use an h22 TB.. I don't want to spend the money on an aftermarket one, and I don't want to use a mustang one either. Anyone know the sizes in mm and application compatibility?

 

H22 wont work. Most aftermarket B-Series TB's are interchangeable. I think the s2000 TB works too with a little modification.
All should work with your IM. You can get yours board out with a new plate.