Jim Meyer Racing supplies the subframes to us. The ones we get are tailored for the BRE TA, but they have one for your Camaro. We will be evaluating the Detroit Speed and Engineering subframe over the course of the next couple of months, and if testing goes well we will be switching to it for future cars. We are doing this primarily because we have a long-standing relationship with DSE and currently carry most of their products, not because of any shortcomings on the JMR subframe.
Keith Maney

Previous 2nd-gen 4-link set ups were adapted 1st-gen F-Body 4 link set ups.  Our latest cars use either a custom Air-Ride or DSE set up, neither of which require a narrow fuel tank.

Here is the DSE kit

http://www.detroitspeed.com/productpages/indproduct/rearsuspensionprod/2ndgenquadra_prod.htm

Give us a call we it can be yours.