1974 A329C transition to A348C Air Filter

[Tom R.]

The 73/74 TIMJG revision team after much deliberation has concluded the following and would like to confirm in support of the revised manual. Your comments are welcome.

In summary:

• Air cleaner assemblies were shipped to the plant with an air filter installed and label attached to the base.
• The transition was limited to L48/L82 with late production (May-June) 1974
• A longer carb stud was required for use with the A348C air filter
• No LS4 left the factory with an A348C air filter

In regards to the A348C air filter, the following reflects the team's findings.

A348C Filter Element PROTECT YOUR ENGINE - REPLACE WITH AC TYPE A348C. Original filters were misted with oil which, contributed to the yellowish appearance.

[Robert S.]

Re: 1974 A329C transition to A348C Air Filter

I have a 32000 mile may 74' built L48 which is quite but not 100% original. I am not the original owner. The quadrajet is the correct p/n for my engine and transmission so I am inclined to think it is original to the car. The air cleaner element is not the original but is the 3 1/2 inch tall type and the sticker on the side of the air cleaner says to use A348C. The length of the stud on the carb from the top surface of the carb where the stud is screwed in to the top of the stud is 2 1/2 inches and seems to be the right length for the air cleaner element. I would say that all this supports, but does not prove, the team's findings. Hope this helps.

[Tom R.]

Re: 1974 A329C transition to A348C Air Filter

I have a 32000 mile may 74' built L48 which is quite but not 100% original. I am not the original owner. The quadrajet is the correct p/n for my engine and transmission so I am inclined to think it is original to the car. The air cleaner element is not the original but is the 3 1/2 inch tall type and the sticker on the side of the air cleaner says to use A348C. The length of the stud on the carb from the top surface of the carb where the stud is screwed in to the top of the stud is 2 1/2 inches and seems to be the right length for the air cleaner element. I would say that all this supports, but does not prove, the team's findings. Hope this helps.

Thanks Robert...that's helpful

What day in May...do you know the trim tag date code? Four-speed or automatic?

[Robert S.]

Re: 1974 A329C transition to A348C Air Filter

The car is a 4 speed. I have the tank sticker and the schedule date appears to be 05-15. The vin is 1z67j4s427597. The car as it sits today agrees with all the data that I can read off of the tank sticker.

[Tom R.]

Re: 1974 A329C transition to A348C Air Filter

The car is a 4 speed. I have the tank sticker and the schedule date appears to be 05-15. The vin is 1z67j4s427597. The car as it sits today agrees with all the data that I can read off of the tank sticker.

That's quite helpful, thx

[David L.]

Re: 1974 A329C transition to A348C Air Filter

I have a square mesh NOS A329C air filter with "BEST WAY TO PROTECT YOUR ENGING - REPLACE WITH AC TYPE A329C" labeled in white on the black plastisol part of the filter in a 1974 AC box.
I also have a diamond mesh NOS A329C air filter with "AC TYPE A329C" labeled in white on the black plastisol part of the filter in a 1992 AC box.
I assume that the 1974 version A348C AC air filter was also the square mesh type.

Dave

[Jimmy P.]

Re: 1974 A329C transition to A348C Air Filter

I have a square mesh NOS A329C air filter with "BEST WAY TO PROTECT YOUR ENGING - REPLACE WITH AC TYPE A329C" labeled in white on the black plastisol part of the filter in a 1974 AC box.
I also have a diamond mesh NOS A329C air filter with "AC TYPE A329C" labeled in white on the black plastisol part of the filter in a 1992 AC box.
I assume that the 1974 version A348C AC air filter was also the square mesh type.

Dave

Yes, the NOS A348C 1974 versions were also square mesh, Dave. I'm sure you are aware that "square mesh" NOS types are very pricey now if you can find them!

[Robert S.]

Re: 1974 A329C transition to A348C Air Filter

My son has a March 1974 built ( data from blue sticker on drivers side door) L82 four speed. He is not the original owner. The engine compartment, including the air filter area parts, appear to be original to the car. The sticker on his filter housing says to use A348C however it is not certain this sticker is the original. The filter (not the original) is 3 1/2 inches tall and the length of the stud measured from the top of the carb is 2 1/2 inches - ie same as my May built 74' that I responded in my earlier email. Hope this helps.

[Tom R.]

Re: 1974 A329C transition to A348C Air Filter

My son has a March 1974 built ( data from blue sticker on drivers side door) L82 four speed. He is not the original owner. The engine compartment, including the air filter area parts, appear to be original to the car. The sticker on his filter housing says to use A348C however it is not certain this sticker is the original. The filter (not the original) is 3 1/2 inches tall and the length of the stud measured from the top of the carb is 2 1/2 inches - ie same as my May built 74' that I responded in my earlier email. Hope this helps.

Robert
Thanks for tracking that down. We believe and have confirmed that air cleaner assemblies came to the plant in an assembly. So if the label says 348C then the assembly would have included the air filter and longer stud to secure it.

Are both these L48s four-speeds? I would be curious if one is an M40, whether it has AIR? BTW, what water temp gauge is installed? I suspect given the dates its a 280 but I like to confirm.

Thanks much for this post.

[Robert S.]

Re: 1974 A329C transition to A348C Air Filter

My car is an L48 4 speed with air and has a 280 water temp gauge I think the trans. is an M40. My son's car is an L82 4 speed with air but I do not know which transmission. His car is in another state so cannot say if water temp gauge is 280 or not.
I assume the 2 1/2 inch stud is correct for a 3 1/2 thick air cleaner - is that correct?

[Tom R.]

Re: 1974 A329C transition to A348C Air Filter

My car is an L48 4 speed with air and has a 280 water temp gauge I think the trans. is an M40. My son's car is an L82 4 speed with air but I do not know which transmission. His car is in another state so cannot say if water temp gauge is 280 or not.
I assume the 2 1/2 inch stud is correct for a 3 1/2 thick air cleaner - is that correct?

Yes, the M40 is the order code for the automatic transmission. Here is a photo of the two studs next to each other. The longer stud is correct for the 3 1/2 inch A348C air filter.