why do Rallye 350s have this hole in the snorkel? i have never seen this hole on any other car. is it just me or is there a reason for it to only be on a Rallye 350?
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I have never noticed that - anything I'd have to offer would be purely speculation. But if that's how it should be then I'm guessing the value of the Rallye 350 bases just went up - can't be that many of those around anymore. Is it a punched hole or a drilled hole - it almost looks like it there is a bit of a relief towards the inside of the snorkel

 

it sure looks to be punched. i don't know if the value would be any higher because you could drill a hole in another one. i have seen several Rallye 350s with it and never seen one on a W-30. i wonder if the W-31 has the hole. i have always wondered this but never thought to ask. i just got an entire OAI breather off E bay that is from a Rallye and that is what reminded me.

my original base had the hole but i ran that base over with the car back in the 90s.

 

Yeah, I wonder if it is a 350 vs 455 item - a hole in there could affect air flow or even make a difference to the sound ie like how a whistle is made - will be interesting to see what people may know about this. OH and to run over yours, I know its just a car but that must have been painful, especially back then, not many around and no repos.

 

when i heard it i about pi$$ed myself. i knew what it was the very second it happened. i was just glad it was the base and not the top. back then the base was much cheeper than the top. to bad i never got a base to replace it till the price of the bases were higher than the top.

while on the subject, what is the correct screw or attachment for the motor to the flapper door?

 

I have that hole in the snorkel of my air cleaner base, although mine is a standard 1970 Cutlass S 2-barrel. A line from the charcoal canister runs to that hole, with a little plastic elbow making the connection. I'm not sure, but it might be exclusive to California cars of that year - part of the Option Code NA-9 Evaporative Control System.

 

Isn't it a rivet, I can check tomorrow.

 

Ive always thought these were for the Cali cars too!

Here is one on EvilBay.

http://cgi.ebay.com/ebaymotors/1970-...Q5fAccessories

Sam

 

Try www.inlinetube.com. Part no. 10399 flapper door rivet kit.

 

Yes, I believe this is exclusive to Calif cars. I owned a 1970 Supreme when I lived in SoCal and it also had the hole in the snorkel and the evap system.

 

i have seen it on Rallye 350 that were not sold in California. did they put the hole in all the small block cars if there were going to use the hole or not. my Rallye 350 was sold in Indiana and had one and the one i just got from E bay (i was told) was sold the his family new in Florida.

 

The hole appears on all OAI metal bases--at least all the '70 bases I have seen (CA or not). It was a lightening hole so the W-cars would be faster.

 

neither 70 base I have has it but I will drill two holes in it, mine will be even lighter and rarer

 

As some have already surmised, the hole on the bottom of the snorkle is part of the California emissions package in 1970. Here's what I found out a couple years ago when someone asked me to research it:

Bingo!!! Mystery solved.
I spent some time with the 1970 Assembly Manual last night and found out what the 1/2" hole at the mouth of the air cleaner snorkel is for.

The 1970 Olds A-bodies had an emissions option referred to in the manual as "35NA9." The manual usually inserts "35" before option numbers (W-30 is referred to as 35W30), so my bet is this emissions option is simply nown as NA9. I think this was only used on California cars in 1970. The option primarily consists of a gas tank venting system, with some sort of contraption mounted back by the tank and a charcoal canister under the hood. And lots of hoses. The charcoal canister has three ports, with one port connected via hose to the snorkel mouth.

A ~45 degree elbow (p/n 3967086, Conn Asm Air Cleaner Purge) inserts into the 1/2" hole in the snorkel, attached with a clip (p/n 3977168). This connection is the same for both single- and dual-PCV systems. No mention is made of OAI, but since most dual-PCV cars were OAI, I'm sure that the California OAI cars used this, too.

There sure are a lot of bizarre little parts needed for the NA9 option. For example, another port on the charcoal canister has to tap into the hose between the PCV and carb. On dual-PCV systems, this hose is only about 3" long, so it is replaced with a rubber "T" with the charcoal hose clamped to it. Good luck finding one of those rubber T's today!

Anyway, since the NA9 option was installed on so few cars, it wouldn't surprise me at all if not all air cleaner snorkels had the 1/2" hole. I doubt the Framingham, MA plant shipped too many cars to California, and I bet they bought their air cleaner bases from a different supplier than the Freemont, CA plant.