12v71 powered Peterbilt 359 with straight pipes! LOUD!

This is a friend of ours peterbilt that i got to ride in. It’s a 1975 Peterbilt 359 and it’s powered with a 12v-71N non turbo and a RTO-12513 tranny and has 5:29 rear ends.. This has 6“ straight stacks on it. Yes, it has true dual stacks on it, no Y-Pipe.