Exhaust?

[69shortcst]

I starting on my swap, a 1999 4.8 and 4L60E into my 69 cst. I've got several questions I would appreciate help with. First what mounts work best for the motor. Also for the tranny, would I be better off getting a whole new crossmember or modding mine (no problems doing the cutting or welding, just want to get it in the right location). My third question is the exhaust. Will the stock exhaust manifolds fit without having to notch the frame. I'm looking for ecomony at the end of the build so I want to keep the motor as efficient as possible. Thanks for any answers you may have.