Does anybody know if the back plate for a 70 (no heat riser no summer/winter flap) air cleaner is identical to the 72 one? The 72 I am referring to is for roundtops and has the heat riser and summer/winter flap. I know it will fit but am concerned with originality as my Z is an early VIN. Thank you in advance....

Interesting, my 1970 (HLS3002126) came with the summer/winter flap on the snorkel. I wasn't aware there were ones without it! Can anyone confirm this?

The one in the picture with the carbs is the early style.

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&rd=1&item=8010277874&ssPageName=STRK:MEWA:IT

No. The backing plates are different between '70s and '72s if you are looking for accuracy. The '72s have an additional vent from the carburetors which is lacking from the '70 style. We were just kicking around the early carburetor conversation. These eBay examples have the drain plugs in the front of the float bowls. They are the later four screw style.

Air cleaner boxes for the early cars, like this eBay example, had no flapper valve and pre-heat hose connection. What troubles me though, is that there is no inner pipe on the backing plate for the crankcase ventilation hose on this one. It looks like the wing nuts are the wrong ones also.

I will also add that I have three different non-snorkle air cleaners. All have slight differences that you would only notice when taken apart. From the outside, they are all sisters. Check out section 11 of the parts fiche.

Here. I found a better picture and drew some arrows to point out the differences. The backing plate on the left is from 26th. The backing plate on the right is from a '71, I think. It has an additional vent tube connection and a clip to hold the vent hose. Interestingly, both backing plates were stamped out from the same die. One has a hole drilled and a clip welded on to areas that are clearly marked with indentations "targets" in the metal. My opinion would be that if your build date is before 7/70, your backing plate would be like mine on the left. After 7/70 would be like the one on the right. I'll tell you who is the real pro at this is Carl Beck. He could tell you better when the change happened.

My build date is 4/70 - thanks a lot guys. There is a cover-only on EBay. I'll keep looking for a complete one.....

The cover on eBay is brand spanking new. No backing plate though.