7.3 Power Stroke Power Guide: Stage 1 and 2 (1994-2003) | Alligator Performance
The 7.3L Power Stroke is loved for its durability, and a few well-chosen parts make it noticeably stronger while towing. The key is respecting its limits: the automatic transmission, and on many 2001-2003 engines, connecting rods that do not tolerate big power. This guide lays out Stage 1 and Stage 2 for OBS and Super Duty trucks, each with a towing build and a max power build.
Pick your truck below to see only the parts that fit it. Every card shows the fitment as it appears on the product page, and parts listed with a CARB Executive Order carry a green badge with the EO number.
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Quick answer: the best power upgrades for your truck
1994-1997 OBS
- Stage 1 towing: Edge Evolution CTS3 plus an S&B intake.
- Stage 1 max power: add a cat-back exhaust.
- Stage 2: an ATS converter and valve body for the E4OD.
1999-2003 Super Duty
- Check for powdered metal rods first (most 2001-2003 engines).
- Stage 1 towing: Edge Evolution CTS3 plus an aFe intake.
- Stage 2: a FASS lift pump and 4R100 upgrades; max power adds the BD Turbo Thruster II.
Before you add power
Start with a healthy truck. Fix high pressure oil leaks, check the cam position sensor and IDM, test glow plugs, and confirm fuel pressure before adding power. The 7.3 does not like low fuel pressure or worn injectors, and extra power only magnifies both.
On 1999-2003 trucks, find your engine serial number. Most 2001-2003 engines have powdered metal connecting rods (serial numbers 1,425,747-1,440,712, and 1,498,319 and up). They are fine at the power levels in this guide, but they can break without warning if you go much past about 400 rwhp.
Tuning and some performance parts can affect your factory powertrain warranty. Check before you install.
1994-1997 OBS
Start with a healthy truck: work through the 1994-1997 OBS maintenance guide first.
1999-2003 Super Duty
Start with a healthy truck: work through the 1999-2003 Super Duty maintenance guide first.
Stock power and where the limits are
Every number below is a factory rating at the crank or a typical figure at the wheels, as noted. "Reliable towing target" is where we suggest a truck that tows stops, so the engine, transmission and cooling system all live a long time.
| Years | Stock rating | Transmissions | Reliable towing target | First limit you hit |
|---|---|---|---|---|
| 1994-1997 OBS | 210-225 hp, 425-450 lb-ft | E4OD automatic, ZF5 5-speed manual | Stock power plus about 50-70 hp with a tuner and supporting parts | The E4OD and the factory fuel supply |
| 1999-2003 Super Duty | 235-275 hp, 500-525 lb-ft | 4R100 automatic, ZF6 6-speed manual | Factory power plus about 60-80 hp; stay well under 400 rwhp on powdered metal rod engines | Powdered metal rods on most 2001-2003 engines, then the 4R100 |
Stage 1: bolt-ons and tuning
Stage 1 is the bolt-on step: tuning (where a legal option exists), better airflow and the gauges to watch what the engine is doing. The towing build is what we recommend for most trucks. The max power build adds the parts that let the same truck make more power without giving up reliability.
1994-1997 OBS
The Edge Evolution CTS3 is covered by CARB EO D-802-13 for 1994-2003 7.3L trucks. It adds power with Edge's preloaded levels and monitors the engine at the same time. Add an S&B intake, covered by a CARB EO for these trucks, and a cat-back exhaust that keeps the factory converter.
Stage 1 towing build
Best for most trucks that tow.
Towing pick
Edge 85400-100 CTS3 Diesel Evolution Programmer
Edge Evolution CTS3 programmer and monitor. Run a towing level when hooked up.
Listed with CARB EO D-802-13
Listed fitment: 1994-2019 Ford F250/F350 7.3L/6.0L/6.4L/6.7L Powerstroke
Check price and fitment
S&B 75-5131-1D Cold Air Intake with Dry Filter
S&B cold air intake with a dry filter for 1994-1997 trucks.
Listed with CARB EO D-590-34
Listed fitment: 1994-1997 Ford F250/F350 7.3L Powerstroke
Check price and fitmentStage 1 max power build
Adds to the towing build for more power.
Diamond Eye K4310A 4 inch Aluminized Cat Back No Tip Exhaust
Diamond Eye 4 inch aluminized cat-back exhaust. Keeps the factory converter.
Listed fitment: 1994-1997 Ford F250/F350 7.3L Powerstroke
Check price and fitment
S&B 75-5131-1 Cold Air Intake with Oiled Filter
The same S&B intake with an oiled filter.
Listed with CARB EO D-590-34
Listed fitment: 1994-1997 Ford F250/F350 7.3L Powerstroke
Check price and fitment1999-2003 Super Duty
Check your engine serial number before anything else: most 2001-2003 engines have powdered metal connecting rods that can fail without warning past about 400 rwhp. Stage 1 stays well under that. The Edge Evolution CTS3 is covered by CARB EO D-802-13 for these trucks, and the aFe intake below is listed with an EO.
Stage 1 towing build
Best for most trucks that tow.
Towing pick
Edge 85400-100 CTS3 Diesel Evolution Programmer
Edge Evolution CTS3 programmer and monitor. Run a towing level when hooked up.
Listed with CARB EO D-802-13
Listed fitment: 1994-2019 Ford F250/F350 7.3L/6.0L/6.4L/6.7L Powerstroke
Check price and fitment
aFe Power 54-10192 Magnum FORCE Stage-2 Cold Air Intake System with Pro 5R Filter
aFe Magnum FORCE Stage 2 intake with an oiled Pro 5R filter. The EO covers 1999.5-2003.
Listed with CARB EO D-550-3
Listed fitment: 1999-2003 Ford F250/F350 7.3L Powerstroke
Check price and fitmentStage 1 max power build
We do not list a cat-back exhaust for these trucks right now; ask our sales team. Turbo-back systems can replace the factory converter section, so they are not part of this guide.
AutoMeter 8444 Factory Match 2-1/16 inch 0-1600 Pyrometer Kit
AutoMeter pyrometer for a dedicated exhaust temperature gauge.
Listed fitment: 1999-2007 F250/F350
Check price and fitmentStage 2: fuel, turbo and the parts that support them
Stage 2 adds fuel supply and airflow, and the supporting parts that keep the extra power reliable. On most trucks the transmission has to be part of Stage 2, so it is included here.
1994-1997 OBS
OBS trucks have no factory intercooler and a mechanical lift pump, and we do not carry fuel or turbo upgrades for them that are covered by a CARB EO. Stage 2 on an OBS is the drivetrain: a converter and valve body so the E4OD can take the power Stage 1 adds.
Stage 2 towing build
Fuel supply and drivetrain first.
Towing pick
ATS 302-950-3104 Five Star Torque Converter, 1300-1500 Rpm Stall Speed, E4OD/4R100
ATS Five Star torque converter with a towing stall speed.
Listed fitment: 1989-2003 Ford F250/F350 7.3L Powerstroke
Check price and fitment
ATS 303-903-3104 E4OD 4R100 Accumulator Valve Body
ATS accumulator valve body for firmer shifts and less slip.
Listed fitment: 1989-1998 Ford F250/F350 7.3L Powerstroke
Check price and fitmentStage 2 max power build
Adds to the towing build for more power.
ATS 302-930-3104 E4OD 4R100 Triplelok Torque Converter
ATS Triplelok triple-disc converter for more holding power.
Listed fitment: 1989-2003 Ford F250/F350 7.3L Powerstroke
Check price and fitment1999-2003 Super Duty
Stage 2 on a Super Duty adds fuel supply and a turbo upgrade listed with a CARB EO. On engines with powdered metal rods, keep the total under about 400 rwhp and use a conservative tune.
Stage 2 towing build
Fuel supply and drivetrain first.
Towing pick
FASS TSF14180F140G Titanium Signature Series 140GPH 55PSI Fuel Lift Pump
FASS 140 gph lift pump with filtration and water separation.
No CARB EO: not legal for sale or use in California
Listed fitment: 1999-2007 Ford F250/F350 7.3L Powerstroke/6.0L Powerstroke
Check price and fitmentATS 302-950-3104 Five Star Torque Converter, 1300-1500 Rpm Stall Speed, E4OD/4R100
ATS Five Star torque converter.
Listed fitment: 1989-2003 Ford F250/F350 7.3L Powerstroke
Check price and fitment
ATS 303-903-3224 4R100 Accumulator Valve Body
ATS 4R100 accumulator valve body.
Listed fitment: 1999-2003 Ford F250/F350 7.3L Powerstroke
Check price and fitmentStage 2 max power build
Adds to the towing build for more power.
BD Diesel 1047511 Turbo Thruster II 50 State Legal Turbocharger Kit
BD Turbo Thruster II turbo kit, covered by CARB EO D-553-2 (22 psi maximum boost).
Listed with CARB EO D-553-2
Listed fitment: 1999.5-2003 Ford F250/F350 7.3L Powerstroke
Check price and fitment
ATS 309-912-3224 4R100 Stage 1 Transmission Package
ATS Stage 1 4R100 transmission package, 2WD.
Listed fitment: 1999-2003 Ford F250/F350 7.3L Powerstroke 2WD
Check price and fitment
ATS 309-914-3224 4R100 Stage 1 Transmission Package
ATS Stage 1 4R100 transmission package, 4WD.
Listed fitment: 1999-2003 Ford F250/F350 7.3L Powerstroke 4WD
Check price and fitmentTransmission and clutch
1994-1997 OBS
The E4OD is less robust than later Ford automatics. Plan on the valve body and converter shown in Stage 2 before you tow heavy at Stage 1 power. On ZF5 manual trucks, the factory clutch is the first part to slip when you add power.
South Bend Clutch 1944-5OKHD Single Disc HD Organic Clutch Kit
South Bend single disc HD organic clutch for ZF5 trucks.
Listed fitment: 1994-1998 Ford F250/F350 7.3L Powerstroke
Check price and fitment1999-2003 Super Duty
The 4R100 handles Stage 1 with a converter and valve body. At Stage 2, a built transmission is the long-term answer. The factory flexplate can fail at high torque, so ask about one with a transmission build. ZF6 manual trucks need a stronger clutch at Stage 1.
South Bend Clutch 1944-6OFEK Organic/Feramic Clutch Kit with Flywheel
South Bend organic and feramic clutch with flywheel for ZF6 trucks.
Listed fitment: 1999-2003 Ford F250/F350 7.3L Powerstroke
Check price and fitmentSafe towing temperatures
Added power means added heat. These are the numbers to watch on your gauges while towing. They are sustained readings, not short spikes on a hill.
| Reading | Normal while towing | When to act |
|---|---|---|
| EGT (probe before the turbo) | Under about 1,200°F sustained | Back off or downshift if it stays above 1,250°F. On trucks with a particulate filter, sustained heat above that risks the filter. |
| EGT (probe after the turbo) | Reads about 200-300°F lower than a pre-turbo probe | Know which probe your gauge uses before you set an alarm. |
| Transmission fluid | 170-200°F | Act at 210-225°F sustained: slow down, downshift, add cooling. |
| Coolant | 195-220°F | Act if it stays over 225°F. |
| Engine oil | 210-240°F | Act at 250°F or more, sustained. |
Emissions and legal fitment
Every part in this guide keeps your truck's factory emissions equipment in place and working. Where a part is listed with a California Air Resources Board Executive Order (CARB EO), the card says so. That EO exempts the part from California's tampering law (Vehicle Code 27156) for the vehicles it lists. An EO covers only the exact part numbers, years and engines it lists, and an EO for a tuner covers only the maker's preloaded tunes: a custom tune is not covered. Each EO covers its part by itself; CARB has not evaluated combinations of tuned parts. Parts marked "No CARB EO" are not legal for sale or use in California on pollution-controlled vehicles. Exhaust that bolts on behind the catalytic converter or particulate filter generally does not need an EO, but local noise rules still apply.
1994-1997 OBS
OBS 7.3 trucks have no EGR or particulate filter. All manual trucks and many automatics have a factory catalytic converter: check the emissions label and keep it. The Edge CTS3 is covered by CARB EO D-802-13 with its preloaded tunes.
1999-2003 Super Duty
Super Duty 7.3 trucks have no EGR or particulate filter. Manual trucks and many automatics have a catalytic converter: keep it. The Edge CTS3 is covered by CARB EO D-802-13 with its preloaded tunes; the BD Turbo Thruster II and aFe intake are listed with EOs.
Shop parts for your truck
1994-1997 OBS
1999-2003 Super Duty
Not sure which parts your truck needs?
Alligator's sales team helps 7.3 Power Stroke owners plan power upgrades every day. Tell us your year, transmission, engine serial number and what you tow, and we will build a parts list that fits.
Call 208-719-7400Send us a messageFrequently asked questions
How much power can a 7.3 Power Stroke handle while towing?
The parts in this guide add about 60-80 hp. On engines with powdered metal rods, stay well under about 400 rwhp, where they start to fail. Forged rod engines have more margin, but the transmission becomes the limit first.
How do I know if my 7.3 has powdered metal rods?
Check the engine serial number on the engine data label. Most 2001-2003 engines have them. Our sales team can help you check yours.
Is the Edge Evolution CTS3 legal on a 7.3?
Yes. CARB EO D-802-13 covers it on 1994-2003 7.3L F-250 and F-350 trucks when you use Edge's preloaded tunes.
What is the first transmission upgrade for a 7.3 that tows?
A torque converter and valve body. On manual trucks, a stronger clutch.
Do I need a lift pump on a 7.3?
On 1999-2003 trucks, a filtered lift pump is the main fuel supply upgrade for Stage 2. On 1994-1997 trucks, the factory mechanical pump should be checked and replaced if pressure is low.
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