In my opinion glasspacks are the way to go on inline 6's. I have a Thrush Magnum 2" O/D 31" long on my '51 Chevy 235, sounds great for being factory single exhaust, tho I will replace it with a smitty's glasspack muffler, I'v heard the 216-235's sound awsome with them and I'm doing a 50's era correct custom, and they were the hot ticket back then. I have a 2" O/D 24" long thrush magnum on my '67 Falcon, it's a 200 I6. the smitty's are $25 a peice, the Magnums are about $20-25 depending on what size and length you get. smitty's is only available in 2" x 24"