GM Turbo 350 (TH350) Deep Transmission Pan – High Capacity Aluminum Performance Upgrade

Enhance the performance and durability of your transmission with this GM Turbo 350 (TH350) Deep Transmission Pan, designed to increase fluid capacity and improve heat dissipation under demanding conditions. Whether you're running a street build, towing, or pushing performance limits, this upgrade helps keep your transmission running cooler and more efficiently.

Constructed from high-quality aluminum, this deep transmission pan provides superior strength and improved heat transfer compared to factory pans. The increased fluid capacity enhances lubrication, reducing wear and extending transmission life—especially in high-stress environments.

Engineered as a direct-fit upgrade for GM vehicles equipped with the Turbo 350 (TH350) transmission, this pan delivers dependable performance and long-term reliability.

✅ Key Features:

• Increased fluid capacity for improved cooling and performance
• Designed for GM Turbo 350 (TH350) transmissions
• Durable aluminum construction for strength and heat dissipation
• Ideal for towing, street performance, and racing applications
• Helps extend transmission life and reduce wear
• Direct fit for easy installation

Upgrade your drivetrain with confidence and enjoy improved cooling, smoother shifting, and long-lasting reliability.

Pan includes magnetic drain plug and mounting hardware.
Price varies with finish.

Volume: 2 quarts over stock

Dimensions: Click here for dimensions. 

Number of Bolts: 13

PML designed this extra capacity transmission pan for the GM TH350 (Turbo–Hydramatic 350) transmission.

Benefits:

• Extra capacity
• Drain hole and magnetic drain plug for easy fluid changes
• Finned for cooling
• Heavy duty sand cast aluminum construction
• Machined flat gasket sealing surface
• Can optionally be machined for a temperture sending unit

PML also makes a stock capacity version of this pan for vehicles that need more ground clearance. The stock capacity TH350 pan, PML part number 9589, has the external bosses that may interfere with the drive shaft on some vehicles.

Applications:

TheTH350 transmission was first available in 1969 after joint development by Buick and Chevrolet. It continued in production in the 1980s. The TH350 transmission is called Turbo 350 in the racing field and is formally called THM350 for Turbo–Hydra–matic 350.

The TH350 transmission is found in GM (Chevy, Cadillac, Olds, Buick) vehicles as well as retrofitted Jeeps and other cars and trucks. For example, this transmission was originally on 1967 to 1972 El Caminos, Blazers, and C/K 20 trucks and Suburbans.

4WD Vehicles: Check for space between drain plug and drive shaft. If the draft shaft will be close to the side of the pan, it could hit the head of the drain plug. PML can drill and tap the other side of the pan to avoid this. Contact us for ordering information with this option.

Drain

The drain hole is on the passenger side of the PML transmission pan. A magnetic drain plug is included with the pan.

Check for drive shaft clearance. The head of the drain plug sticks out about 5/16ths inch. On some 4WD vehicles, the drive shaft runs close to the edge of pan. If needed PML can move the drain to the other side of the pan. Contact us for ordering this option.

Filter

This PML pan works with the stock filter.

The filter bolts on to the valve body so no filter supports or extensions are needed.

Gasket

PML recommends a cork or cork composite gasket with this transmission pan. There are many available. For example, this cork/rubber composite gasket is Mahle Part Number 39348 and was purchased on Amazon.

   
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Optional Temperature Sending Unit Machining

Optionally, PML can drill and tap a 1/8 NPT hole for a temperature sending unit. This would be for an aftermarket temperature gage. There is a custom machining charge.

There are two possible locations on this pan. There is a boss (thick area) on both the driver and the passenger sides of the pan for this.

Select the option before adding pan to cart. A plug for the hole is included.

The standard size is 1/8 NPT. Check your aftermarket gage to verify the thread specifications for the sending unit before ordering. Call or email if you need a different size.

Revisions

In 2014, PML moved the drain plug and bosses for an optional temperature sending unit. These were on the outside of pan and are now on the inside. The external bosses interfered with the drive shaft on some vehicles. The polish finish pan still has the bosses on the outside of the pan.

Check for drive shaft clearance, especially on 4WD vehicles. The head of the drain plug sticks out about 5/16ths inch. On some 4WD vehicles, the drive shaft runs very close to the edge of pan. If needed PML can move the drain to the other side of the pan. Contact us for ordering this option.

PML Transmission Pan Compared to Stock

   
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