Do what Chryco says and take some measurements.
You got a TKO? I think that is what I spy in your pics.
What is your engine/trans angle? I've got a TKO, BB, and have 5 degrees down - my Dougs headers looks like yours. I plan to raise up the transmission like 73_Cuda_4_Me mentions. Shooting for 3 degrees - about 1" in spacers. Raising the trans with a jack just 1/2" tucks in the headers nicely,