Trying to get that specific exhaust sound

[89GMCJOHN]

Without a cam of at least around 274 degrees up you arent going to get that exact sound . That pop n chop is all compression and duration. The closest you can get IMO with a tame cam is to run short dual flowmaster 2 chambers and dump them with stubby downturns right at the rear axle under the truck . Ps you will hate it after 6 months due to the cab drone and want a quieter setup lol ..... FWIW.

 

[RichLo]

Long tubes, H-pipe, and flowmaster 40s. All mandrel bent tubes either dumped or full length, up to you

The H-pipe gives more of a 'classic' sound over the X-pipe.

 

[Chevy-SS]

Here's a little web site I made a few years back when I sold my '68 Camaro. It had 468ci engine with lots of goodies. All the components are listed, as well as some videos with idling and some hole shots. This will give you some info, I think: http://csgbenefits.org/camaro/index.htm

Personally, I favored the big Flowmasters and x-pipe, with equal-length long-tubes.