Muffler installation advice sought by a newbie

[PrairieDriver]

I am installing a Bischoff muffler to replace a mysterious muffler set up installed by the previous owner. I bought a used muffler on the ESR classifieds and have two questions that have arisen as I try to install it:

1. Loose debris: there seems to be loose soot or some sort of material inside the muffler. It sounds like sand sliding in the muffler. I can shake some of it out (debris falls out of the two heat exchanger mounts), but not all of it. Should I worry?

2. Fitment: is there a trick to fitting the muffler under the rear valance (i.e., the body part where the license plate mounts)? I am reluctant to force it, but I don't see how to fit the muffler into the void between the muffler mounting bracket and the rear of the car. Newbie confession: the Bischoff is from a 1975 car; my car is a '71. I thought the routing of the exhaust tip was the only difference from a fitment perspective, but perhaps I am wrong.

Thanks for any advice. I'm enjoying getting to know my car but have much more to learn!

Howard

[RSTarga]

Remove the license plate valence.

[PrairieDriver]

Thank you. I didn't realize that this project would bring me into a new realm: removing and replacing a body panel. Fingers crossed! Should be interesting.

And I gather that I don't need to worry about the loose debris.

Howard

[Bill Meyer]

Shouldn't need to remove the license valence, it just makes it easier. It's been awhile for me on an longhood 911, but just angle the rear seam of the muffler upwards and past the valence first, then angle the exhaust inlets up to line up with the heat exchangers. Fairly simple really.

Also, that 75 exhaust outlet will angle down pretty far, so not sure if you'll like the look.