Unfortunately there isn't one. The AC ZS1 filters are now obsolete stock and there is no alternative. They sometimes turn up at autojumbles or eBay. Very occasionally some ex-military unmarked ones turn up and these do not have a manufacturers id on them.
1=gm division=chevrolet, z= series=corvette, l98=L98 engine
Yes! In the 1970's it was a TV show in the UK. It was a "how things work" type of show which had 4 presenters. Each had a speciality, science, nature, etc. The theme tune was an Indian chant and ended with all the presenters holding up their right hand and saying "HOW". The presenters were called Jack Hadgreeves and Fred Dinage Check out.... http://www.youtube.com/watch?v=zS1-aoUNBbE