There's some footage in this most recent video of the engine. Video's only a a couple years old but there is another from 11 years ago with the following description
I pulled this info from various videos of his ...
72 240z, 2.8 L Motor, Webber Dcoe 40's, big cam, 4.44 LSD, Open Pipe - its a very old motorsport set 3-2-1 there is a 3 inch resonator and 2.5 inch all the way back ... the sound is the motor which is a monster
72 240z, 2.8 L Motor, Webber Dcoe 40's, big cam, 4.44 LSD, Open Pipe
we discovered the old 70's era turbo muffler was pretty restrictive. the car is a little louder now but pulls way harder all the way to redline. 2.8l block, ported head, big cam, dcoe 40's, header, msd6 al, 10lb flywheel, 4.44 plated subaru r180 lsd diff, 5 speed
cam came out of a race car
still running the old motorsport header from way back... it runs 3 into 2 then it merges just before the resonator which is half way down the car... under the drivers seat... then the pipe runs back over the axle to where an old turbo muffler was ... we saw-z-alled that off and installed a bolt on flange so we can install a muffler if we get pulled over ... from the joint it runs about 2 feet of 3inch pipe ...which really helps drop the rice out of the sound
Motor is a fully built 2.9l with webers and a big cam ... the exhaust is 2.5... until the point where the muffler used to be then its a 3 inch tip ... there is a resonator in the mid pipe
Headers into a resonator & then out to the back 2.5 inch opens up to 3.5 for the last 2 feet, the different pipe diameters and the 3 weber carbs (ITB's in modern talk ) are a big part of the sound