On my daily 235 with Fenton headers I started out years ago with generic muffler store brand glasspacks 30" - too quiet, no tone.

Been driving around with repro Smithy's 22inch for two years now - still too quiet.
These are not anywhere close to the original steelpacks they got their reputation from lasting until today. Ask any rodder from the days.
The repros have thin cheap metal and have a dead plastic thud sound when you knock them. That's also how they sound even after 2 years of break in.
The old water into hot mufflers or burning the fiberglass with gas or lighter fluid tricks also don't work like with 60s glasspacks.

Tried straight pipes, but too obnoxious for a daily...two words: raw thunder, peeling off the skin of your face if you get too close. Cool for shows or meets though.

If you want an amazing tone treat yourself to Brockman Mellowtone mufflers !!
These are made to order and cost as little as smithy's.
They make them from 12-30 length with either glass or steel or NO packing.
4 rows of louvers twisted into a spiral.
These guys are artists!

I love my new 17" steelpacks.
Idle, revving, going uphill and deceleration sounds amazing. You really know you got a straight 6 going onto the freeway with WOT.

I make instruments for a living and finally I can enjoy the true 'musicality' of my inline 6.

I am not affiliated with these guys in any way, but gotta let others know about them.
Great people - really into what they are doing.


On the road every day...
1952 Truck - 235
1948 Coupe - 261