[L78steve]

Originally Posted by William

In production, L34, L35, L78 & both COPOs used the #6485235 air cleaner assembly. Also used on Z/28 with an extension not used on 396/427. So it is not particularly rare.

Sometime after July '69, the base was revised with a bead to raise the lid for better air flow. Cars built after that time should have the revised base. GMPD serviced the 2nd design #6485235 well into the '80s with another revision; a vent tube with 2 45º bends to clear a Holley double-pumper. GMPD also serviced the seal flange but mostly the version used on Chevelles, notched to clear a vacuum pod used on A/C cars.

Your unit has an original flange. The flat-bottom base is a plus but needs a little work and a lid as noted and is rusty. I suspect that isn't the original seal. Were it complete and in excellent original condition, it would be a great find.

Working against you, the flat bottom ZL2 air cleaner, lid, flange and seal are nicely reproduced for about $250.

Not to start an argument but I believe the raised bead on the floor of the base is for improved sealing.
I cannot see how that would improve airflow.
Granted the repop is nice but its still a repop.