M1 Air-Gap Intake Manifold for a 340 motor

[John K]

I know this topic weaves through a lot of forums, but I've spent hours looking for a definitive answer and had no luck. I have a 1970 Duster with a 340 and have been looking for an M1 Single Plane Air-Gap intake manifold to put on it. The problem is that I don't know the proper part number/casting number for my application. I have LA heads that are stamped with the letter "O" and I have seen at least three (3) similar casting numbers that are very similar but I don't know their differences. The numbers are P4452891 (I think this is the one I need), P4452893 (I see this one a lot), and P4452898. I've also seen a P4876334 but I think that is for W5 heads. Can anyone help me understand the difference and let me know which one is right for my car? I know they aren't made anymore and are hard to find but I have found a few of the P4452893's out there, just not sure they'll fit on my set up. Thanks in advance for your help.

 

[forphorty]

p4452893, Standard or W5 intake

 

[GTX JOHN]

Ken Etter (Famous Superstock Racer) has the correct one for sale.
I believe he is asking $300.
He is a engine builder at Bob Mazzolini Racing in Riverside
and an old friend.
I am not allowed to give # on this site.

 

[12many]

I know this topic weaves through a lot of forums, but I've spent hours looking for a definitive answer and had no luck. I have a 1970 Duster with a 340 and have been looking for an M1 Single Plane Air-Gap intake manifold to put on it. The problem is that I don't know the proper part number/casting number for my application. I have LA heads that are stamped with the letter "O" and I have seen at least three (3) similar casting numbers that are very similar but I don't know their differences. The numbers are P4452891 (I think this is the one I need), P4452893 (I see this one a lot), and P4452898. I've also seen a P4876334 but I think that is for W5 heads. Can anyone help me understand the difference and let me know which one is right for my car? I know they aren't made anymore and are hard to find but I have found a few of the P4452893's out there, just not sure they'll fit on my set up. Thanks in advance for your help.

The only two intake part numbers that you need look for is:

P4452891: has the water outlet in the center with angled bypass outlet like all LA intakes. Bolts right on.

P4532851: has the smaller water outlet offset and the bypass outlet is parallel (points straight forward)
Will bolt right on an LA, the original bypass hose takes a little contorting to get it to fit the outlet stub, no big deal. It fits.

I thought we all explained this to you last year? Not sure why confusion remains?

Mopar Performance M1 Intake for 340 motor

I’d quit digging and focus on the two part numbers mentioned above only. Confusion ends.

 

[John K]

The only two intake part numbers that you need look for is:

P4452891: has the water outlet in the center with angled bypass outlet like all LA intakes. Bolts right on.

View attachment 1715983326

P4532851: has the smaller water outlet offset and the bypass outlet is parallel (points straight forward)
Will bolt right on an LA, the original bypass hose takes a little contorting to get it to fit the outlet stub, no big deal. It fits.

View attachment 1715983328

View attachment 1715983329

I thought we all explained this to you last year? Not sure why confusion remains?

Mopar Performance M1 Intake for 340 motor

I’d quit digging and focus on the two part numbers mentioned above only. Confusion ends.

Wow, you're right. My apologies, must be a senior moment.