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I've spent the afternoon in the archives and found that the OAI assy used in 1970 used the same basic air cleaner base as a non OAI 442. (thank you Patton) That is all goodness however, I'm still needing info on how one would differentiate between a repop flapper top vs an original. I've seen molded in part numbers and dates on supposed originals. Do the repops also have these features? I assume so, because I've also read that there are some variances in the flapper door hinge configuration. If the presence of a molded part numbers alone could distinguish an original top, the hinge configuration would be a mute point.
I don't have a definitive answer as I don't have a repro flapper assembly here to compare to originals. I DO, however, have a repro flapper door from The Parts Place and while it is a nice copy of the original, it does have some minor differences when compared to an original flapper door I have here as well.
As far as the PN's molded into the OAI main part and the flapper door......the TPP flapper door DOES have the same PN molded in on the underside of the door as well as the "sunburst"/clock feature with "70" in the middle of this date molding. And, it's all in the same location on the underside of the flapper door as the original.
I can say that the original OAI bases are a VERY shiny/glossy black plastic at least on the outer vertical "walls" of the piece. I have quite a few originals here and they're all very shiny on those parts. Seems like the repro main piece may be a bit duller/less glossy black plastic but I only really remember observing this when it comes to the horizontal flat top surface.....where the door is and the "OLDSMOBILE" lettering is (and all the surfaces in b/n). Used originals I have seem to have been similar but you would expect that to possibly happen over the years with wear and tear, heat and occasional wiping off of dirt, etc on this upward-facing horizontal surface. I just don't have a perfect one (like an NOS unit) to know if that large surface on the top of the flapper was originally really glossy/shiny as well.
I do believe the repro units have the "sunburst" date code clock and PN molded in on the underside as well......probably in the same location as the originals but I don't know that 100% either.
Can't give a definitive answer but those are some of my off-the-cuff observations. Besides, nothing better to do while listening to the ice and sleet come down outside right now!
I can post some pics of the flapper door differences tomorrow if you want to see those.
Thank you again Patton for your observations. I'm always looking to learn something and am looking to buy an original top end for the OAI air cleaner. I expect to pay more for original but don't want to get duped in paying more for a repop. There was something in the archive mentioned about the hinge configuration being different. Do you see any variance between the repop door and an original in the hinge area?
I believe the OAI base has a shorter snorkel on it, as well as 5 drain holes, two holes for breathers on the side and a hole in the snorkel for some California emission part.
Here you go. Very minimal differences on the flapper hinge or anywhere else for that matter. I would say the repro is a bit shinier than original but not too much. Parts place claims they are original manufacturer? Reproduction also has some small molding circles originals don’t have. Also the raised ribs on flapper door have some nubs on them. I think this is a good alternative if you don’t have an original. No one will know. And yes friend painted es white letters years ago after seeing pictures of Olds promotional pictures. First picture is original. Second repop.
Anyone have access to an original style pin and push nut on vacuum? The one original top we have has a plastic weatherstrip type stud and a 4 hole push nut. I’m guessing the stud is wrong but nut is so oddball it’s probably correct.
the two parts place tops we have one has a metal pin and push on nut. The other it’s completely missing. Of course the Parts place is not willing to help.
first picture original. Second parts place
The lower of the reproductions has a minimumaly shorter snorkel. You could never tell with the naked eye. It’s a pretty nice piece other than the flat paint. Originals were glossy as hell.
FWIW - I wouldn't hesitate to use the repro flapper assembly on a super nice show car....quite frankly, they rank as one of the best/most correct appearing repro pieces made for our cars. They really did a superb job on these and you'll probably never find an original that looks really "new". It'll be full of scratches and scuffs, etc and you most likely won't ever get it back to looking "new".
Then again, I understand wanting the "real thing". As far as the base.....not quite as nice of a repro (compared to the flapper assembly) but still a very nice job.
The repro flapper assembly is something I would call a relative bargain.....it's a prominently placed/viewed part and you get a finish ie - new, no scratches, etc) that would be extremely hard (if not impossible) to duplicate with a used piece. You can't paint a used piece and have it look "real". You can sand and buff but it still won't look perfectly new like the repro.
As far as the pushpin setup....I don't know 100% what the originals were in terms of finish, etc. I make my own but don't have an original to compare them to. ILT (and maybe others) probably have similar...metal pushpins with the metal push-on retainer.
Anyone have a 100% KNOWN ORIGINAL pushpin/retainer?
Posted photos of my flapper assembly Basically cleaned it polished it
Also replated original vacuum pod all fasteners are original to this unit
Go to tread red w 31 in major builds and resto
Hope this will help
Alain
Also, while the year indicator on the flapper is helpful, here is an example of an early flapper door and motor from Oldsmobile that is a bit different. This is a very early piece.
I recently learned that the reproduction base is easy to spot based on the letters stamped on to the snorkel.
I'm running the Parts place setup. In case it helps anyone (since I see people ask about running with taller intakes) - here are some pics with a drop base welded in. I run the Torker intake and Go EFI 8 FiTech. Everything functions as it should. Love the sound when the flapper opens at WOT. Also like to hear the flapper "click open" when I shut the motor off. I have tried WOT runs with the breather setup removed and can't feel any difference in the butt dyno but nothing beyond that yet.
Posted photos of my flapper assembly Basically cleaned it polished it
