They will pass over the crossmember on each side before coming together. You could always come over here to have yours done, it is not a bad drive.
You would lose a little low end torque with the 1 7/8" and Dual 3". You could just use the Kooks Y-Pipe hooked to the stock Cat Back until right before you install the Maggie.
I was able to put it all together in stages because of it being all apart. It would be easy to drop the transmission cross member and slide them up in from underneath.Joe did you have to lift the motor or undo the trans mount to install the headers or did they just slid in from underneath? I have heard it done both ways. Did you take the wheel liners out to have more room? Thanks