'
Comparing yours w/ this Round Port set reported as 68-72 from this thread...
https://www.yenko.net/forum/showthread.php?p=1237317 , tube routing appears similar other than 2'nd from front Driver's Side and Pass' front, likely for AC/Alt/Smog pump clearances but Cool is how yours appear way longer total length.
So, possibly 64-67 or later if few accessories also longer length needs more investigating...maybe off-road pipes?
Best of luck confirming what you have, M/T Super Scavengers are Super C
L!
~ Pete
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