One heatriser on drivers side. 1 1/2" drop base. Routing was specific to that aircleaner, ink stamp was near the flat spot with the vent hole. Many original aircleaners the ink stamp has been painted over.
The pic in post 16 posted 2 years ago is a '70-72 D port dual snorkel Formula base.
https://forums.maxperformanceinc.com....php?p=6314242
70 F-body bases may not have the hole for the bowl vent early in 70 production. I've had quite a few of the Formula dual snorkel aircleaners, but several were picked up off boneyard shelves & at swappers & were not easy to pinpoint model year. I have had at least two 70's with a molded plastic nipple type plug which was used in the vent hole. Have also ran across these on later 70 model production A-GP dual snorkel aircleaners. With the small plug popped out, the same aircleaner base was used on CA emission 70 Qjets. If you need further pics or measurements, feel free, drop me a PM.