The TNT372 72mm T4 is a journal bearing turbocharger built to order in Canada, featuring billet compressor and turbine wheels machined from forged 2618 aluminum. At 72mm this is where the 300 frame stops being a bolt-on and starts being a build decision — it moves serious air for the frame, and the rest of the truck has to be ready for it.

Key Specs

• 72mm (2.83") inducer, billet compressor wheel
• Maximum 1,140 HP (crank)
• 360-degree thrust bearing with increased thrust surface area
• Optimized compressor stage aerodynamics
• 4" inlet, 2.5" outlet compressor housing
• Boss cast and pre-tapped for a rotor speed sensor
• Standard 1/8" NPT pressure port (may need to drill through)
• Available with 76x68, 80x73, or 82x75 turbine wheel, T4 flange (.88 A/R open or .91 A/R divided)
• Interchangeable with existing turbine housings for upgradability

Replaces / Cross-Reference

The TNT372 is a direct bolt-on replacement for S371 and S372 turbochargers and other 72mm 300-frame units. Built on the same frame, it uses the mounting hardware you already have:

• Turbine inlet: T4 bolt pattern — fits your existing T4 manifold
• Turbine discharge: 4.25" marmon — same flange and clamp. Do not undersize the downpipe at this level; 3.5" or 4" is the sensible choice.
• Compressor discharge: v-band, sized to your charge pipe
• Oil drain: 50mm (1.97") bolt centre, mid frame — 12AN recommended on hard-worked builds

Full model mapping: S300 replacement cross-reference.

What Changes at 72mm

The fuel system has to keep up. A 72mm compressor can move more air than a lightly modified fuel system can match. Buying this size without the fuelling means paying for airflow you never use — and paying for it in spool.

The turbine wheel becomes a real decision. With all three wheels available, a TNT372 can be configured as a relatively responsive street turbo or a top-end-biased strip turbo. Two builders can own the same TNT372 and describe completely different turbos. The 76x68 on a 72mm compressor is an intentional mismatch — you are restricting the exhaust side to buy response. It works, as long as you know that is what you are doing.

The drain works harder. Higher boost and sustained load put more demand on oil return. This is the size where stepping from 10AN to 12AN starts being worth the routing effort.

TNT372 or a Small 400-Frame Turbo?

This is the point in the range where the question becomes legitimate rather than premature. Stay with the TNT372 if the truck is street driven, response still matters, or your T4 manifold and downpipe are already set up for the 300 frame — changing frames means moving the turbine discharge from 4.25" to 4.62" and the drain bolt centre from 50mm to 50.8mm. Look at a small S400 if the build is strip-biased or you have not bought the manifold yet.

Full comparison: S300 vs S400 Turbo

Frequently Asked Questions

What turbine wheel options are available?

The TNT372 is available with a 76x68, 80x73, or 82x75 turbine wheel, in T4 .88 A/R open or .91 A/R divided configurations.

How much horsepower will a TNT372 support?

Up to 1,140 crank horsepower. That is the compressor ceiling — what the 72mm wheel will support at the edge of its map — not a build target. Past roughly 820 HP we would generally move you to a 400-frame turbo, which makes the same power with less strain.

Is the TNT372 a direct replacement for an S372?

Yes, for a T4 S371 or S372. The T4 bolt pattern, 4.25" marmon turbine discharge and 50mm (1.97") mid-frame oil drain bolt centre all carry over. A T3 turbo requires a new T4 manifold.

Do I need a bigger fuel system for a TNT372?

A 72mm compressor can move more air than a lightly modified fuel system can match. If the fuelling has not been addressed, the extra airflow over a smaller size goes unused while the spool penalty is still paid.

Should I run a 10AN or 12AN drain?

12AN is worth the routing effort at this size on hard-worked builds. Higher boost and sustained load put more demand on oil return than the smaller sizes in the frame.

Is this turbo built to order?

Yes. Every TNT372 is built to order, assembled and balanced in Canada.

Power ratings on this page are quoted in crank horsepower (HP). Figures previously published in wheel horsepower (WHP) have been restated using our in-house tested conversion — the hardware and its capability are unchanged.