A question of quiet
 

So I have this old 350 (1974) that I recently got running. It currently has an EMGO megaphone muffler that is just too noisy.
So I'm thinking of getting a pit bike muffler like the one in the picture - it has a 38mm inlet that matches my pipe.
But can anyone tell me if it's really going to tone down the racket or am I throwing away my money?

Cheap
Small
Quiet

The basic chart of buying an aftermarket muffler. Pick any two. If you find one that ticks all boxes do tell.

More straight answer, unlikely. Pitbikes aren't trying to be quiet, that's really more a spark arrestor than an actual muffler.

Good point.
I am not married to it being cheap or small.
I'd just hate to spend a lot and it still be loud.

I am open to suggestions...

You might just have to repack it with insulation to get it working the way you'd like it to, but that shouldn't be a problem, just drill out the rivets, and then re rivet when done.

By "it" do you meat the pit bike muffler?
What insulation?
Fiberglass?

Yes, the pit bike muffler; usually fiberglass, they use a special kind for mufflers, it shouldn't be too crazy expensive.

I have what appears to be that same one. Was going to use it on a project but it was way too loud. Just a straight through glass pack.

Not trying to be funny. Go get one for the 2020 klx300r. That is the quietest muffler on a dirt bike I've ever heard. Probably $$$$ but dang it is quiet.