Mopar Performance M1 Intake for 340 motor

[John K]

Can someone please tell me the serial number for the M1 Single Plane Intake that fits a 340 LA engine (not W2 heads)? I'm having trouble finding which one will bolt up to my motor. Also, does the port for the water neck belong in the middle or set off to the passenger side? I have a 70 Duster 340 4 speed and I'm looking to upgrade. Thanks and feel free to ask questions if more information is needed. I see so much conflicting information on this topic.

 

[rumblefish360]

M1 single plane or dual plane?

M1 dual plane P4629116
M1 single plane P4452891

Water neck/thermostat locations were normally centered like stock. The last run of the intakes were more Magnum like than LA. But still use a LA thermostat housing.

 

[John K]

M1 single plane or dual plane?

M1 dual plane P4629116
M1 single plane P4452891

Water neck/thermostat locations were normally centered like stock. The last run of the intakes were more Magnum like than LA. But still use a LA thermostat housing.

Thanks, that's very helpful.

 

[John K]

M1 single plane or dual plane?

M1 dual plane P4629116
M1 single plane P4452891

Water neck/thermostat locations were normally centered like stock. The last run of the intakes were more Magnum like than LA. But still use a LA thermostat housing.

Single Plane, not W2 heads.

 

[John K]

M1 single plane or dual plane?

M1 dual plane P4629116
M1 single plane P4452891

Water neck/thermostat locations were normally centered like stock. The last run of the intakes were more Magnum like than LA. But still use a LA thermostat housing.

How is the P4452891 different from the P4452892 and the P4452893? I see a lot of the P4452893's available, are they similar or different bolt patterns?

 

[rumblefish360]

How is the P4452891 different from the P4452892
P4452893?

891 - Standard, Edelbrock, Trickflow & Chink heads.
892 - 893 I can not find those numbers in the parts catalog.
Where have you seen these?
Single plane intakes numbers for all the small engines;

 

[rumblefish360]

“Race intakes”

 

[12many]

M1 Single Plane P4452891 as shown in the MP Engine Book (1998):

MP Single Plane P4532851 Which was the last version for the LA engine. Only change: water neck was moved, an is the smaller size like the soon to come Magnum engines. (Carb opening shown was owner modified to square bore, they are all spread bore as cast)

These are the only single plane Mopar Performance intakes to be concerned with for the LA engine. Get the correct size water outlet and thermostat for the intake and you’re good to go.

 

[John K]

891 - Standard, Edelbrock, Trickflow & Chink heads.
892 - 893 I can not find those numbers in the parts catalog.
Where have you seen these?
Single plane intakes numbers for all the small engines;
View attachment 1715817985

I've seen the actual 893 manifolds being advertised for sale on Facebook Market Place and eBay. The have the offset water neck placement, but seller says it fits a 340 LA heads car. I sense the 893 has a different bolt pattern, possible for Magnum heads or W5 heads, but I don't know that for sure. That's why I'm asking for help. I saw a Mopar HP Intake Manifold Casting chart listing the 891 as the Manifold kit # and 892 as the casting #. The further I dig, the more confusing it gets.

 

[John K]

M1 Single Plane P4452891 as shown in the MP Engine Book (1998): View attachment 1715818051

MP Single Plane P4532851 Which was the last version for the LA engine. Only change: water neck was moved, an is the smaller size like the soon to come Magnum engines. (Carb opening shown was owner modified to square bore, they are all spread bore as cast)View attachment 1715818056

These are the only single plane Mopar Performance intakes to be concerned with for the LA engine. Get the correct size water outlet and thermostat for the intake and you’re good to go.

Thank you for the article. It seems like the 891 is the manifold I need. Now, if I can just find one in good condition.

 

[12many]

Thank you for the article. It seems like the 891 is the manifold I need. Now, if I can just find one in good condition.

If you’re not running a/c or concerned with where the thermostat sets on the late version, other than sourcing a smaller housing (thermostat) both the regular outlet radiator hose fits without kinking or being twisted, and the bypass hose as well. Been there, done that. I mention only for the fact that if you run across the late intake I’d grab it and roll.

 

[rumblefish360]

I hear ya man! Lots of variations. Wait until you research the W2 head Varieties! I have both W5 intakes that I can check later. If ya want….

In 12’s post, the book shows the normal LA thermostat housing and his picture shows the newer thermostat housing after the magnum came out but it is not a Magnum intake.

 

[Howard1784]

Good luck finding a high flow thermostat. I tried several to no avail. They were all to big. Ford, chevy and mopar dont fit!

 

[Rat Bastid]

Good luck finding a high flow thermostat. I tried several to no avail. They were all to big. Ford, chevy and mopar dont fit!

Stewart Components has high flow Tstats in the magnum diameter