Found some info to share with you.
Those are Benders first edition Quads(9000-9300rpm).
I have the second edition (8750-9000 rpm) which has longer head pipes and flanges and a different tailpipe configuration.
Both editions make the same aprox hp.
Bender also made F111 pipes which ran at 9750 RPM.
There is also unconfirmed rumors of improved stock quad pipes which were again, different.
All pipes were for either the 750 or 800