A boat with logs and snails WILL NOT pass sae J1970. However, that is usually overlooked.

With open headers, the only thing you can do it 'try to comply' with the law.

I don't know how Alabama law enforcement is about noise, but here at the river, (Bullhead City, AZ) as long as I have some form of insert, they left me alone. Been checked 3 times for baffles.

I used Speedway motors 'augers', and cut 2 of the augers off. Drilled the only auger left, full of half inch holes. Mine are 3.5" collectors. Bassett has 4" collectors.

https://www.speedwaymotors.com/Speedway-Auger-Style-Muffler,1736.html

Also try Jet Boat Performance
Or
C.P. Performance

Hope this helps.

Dan'l