Slant Six Glasspacks?

Glasspacks are like any other muffler. The longer the body is, the quieter they are. Since glasspacks are LOUD anyway, I would be careful. You should go longer than normal with a glasspack. I don't think I would use less than a 24" body. And that's the BODY length, not counting the inlet and outlet. Glasspacks can sound good if you do it right, but if not, they sound like total ***, especially on a six cylinder.