The SPOOLOGIC SL-700-001 is the complete, top-side conversion kit that takes an early 1999 7.3L Powerstroke — with its smaller 4-bolt GTP38 compressor housing, smaller pedestal, restrictive spider, and small 2″ plenums — and converts it over to the desirable late ’99-2003 setup with the 5-bolt GTP38, .84 A/R turbine housing, high-flow spider, 3″ plenums, silicone boots, and heavy duty 304SS bellowed up-pipes. Every component in the kit is built brand new by SPOOLOGIC — not remanufactured — and every piece that has a finish (turbo compressor housing, intake spider, and plenums) is available in Raw, Black, or Red so the customer can color-match the entire intake side of the engine.

This is the correct kit for the early ’99 owner who wants the airflow, throttle response, boost control, and exhaust integrity of the late ’99-2003 truck without buying a different truck. It’s a single-purchase path from the early platform to the platform every 7.3L performance part on the market was designed around.

⚠ CUSTOM TUNING RECOMMENDED

Custom tuning is highly recommended to get the full potential out of this turbo. The SL-700-001 will physically bolt up and run on the factory tune because it’s built on the same GTP38 platform as your OEM turbo — but the factory calibration is written for the factory wheels. It does not know how to take advantage of the larger billet compressor, the S300-style turbine shaft, the 1.0 A/R housing, or the upgraded internals. You leave a meaningful amount of airflow, response, and top-end on the table without a tune.

To unlock what this turbo was built to do, plan on a custom tune from a qualified 7.3L Powerstroke tuner. SPOOLOGIC does not supply, write, sell, or assist with custom tunes — please line up your tuning shop before the install if you want the truck to perform the way this turbo was designed to.

Power Support

The SL-700-001 is built to cleanly support up to ~400-500 rwhp when paired with proper tuning, fueling, and supporting modifications. Remember: a turbo doesn’t make power on its own — tuning and fueling make power, and the turbo’s job is to support what the engine is producing. The Stage 1 is sized to keep up with mild-to-moderate tunes, larger injectors, and supporting mods without surging, choking, or overspeeding.

Why the Early ’99 Owner Wants This Conversion

The early 1999 7.3L Powerstroke and the late ’99-2003 7.3L are the same engine block, same heads, same crank, same rods (both use the desirable forged rods — the powdered rods didn’t show up until late 2000-2001). Where the two split is on the top of the engine: the induction system, the turbocharger, the pedestal, and the exhaust up-pipes. Ford quietly rolled the entire top-side over on 12/07/1998, and everything the aftermarket has developed since — every turbo upgrade, every tuner, every intercooler pipe kit, every intake plenum — was designed around the late ’99-2003 hardware. The early ’99 got left behind.

Here’s exactly what’s different on an early ’99 versus a late ’99-2003, and why every one of those differences is a bottleneck:

• Turbo compressor housing (4-bolt, smaller outlet): The early ’99 GTP38 uses a 4-bolt compressor housing with a smaller compressor outlet. The late ’99-2003 GTP38 uses a 5-bolt housing with a larger outlet that flows more air and mates to the larger 3″ intercooler and intake plumbing. You cannot bolt the larger late-style turbo to an early ’99 pedestal — the front of the compressor housing physically hits the early pedestal casting. This is the #1 stopping point for early ’99 owners trying to upgrade one piece at a time.
• Turbine housing A/R: Early ’99 uses a larger A/R turbine housing. The late ’99-2003 uses a tighter .84 A/R that builds boost faster and holds it steadier. The tighter A/R is why the late trucks feel more responsive off the line.
• Turbo pedestal: The early ’99 pedestal is dimensionally different and will not accept the late ’99-2003 turbo. Any late-style turbo upgrade (SPOOLOGIC SL-100-007, Garrett stock replacement, GTP38R, aftermarket ball-bearing units) requires the late-style pedestal to physically clear the compressor housing.
• Intake spider (Y-collector): The early ’99 spider is a smaller-passage casting with 2″ outlet ports feeding the plenums. The late ’99-2003 spider has larger 3″ outlet ports and a straighter internal flow path. The early spider is a hard restriction on any airflow upgrade downstream of the turbo.
• Intake plenums (2″ vs 3″): The early ’99 plenums are 2″ ID. The late ’99-2003 plenums are 3″ ID — a 125% cross-sectional area increase per plenum. This is the single biggest airflow bottleneck on the early ’99 top end.
• Spider-to-plenum boots: The early ’99 uses tapered rubber boots (3″ at the plenum end, 4″ at the spider end) to bridge the mismatched sizes. The late ’99-2003 uses straight 4″ boots. The tapered early boots crack, swell, and leak boost like every rubber boot on a 25-year-old truck.
• Up-pipes: Both early ’99 and late ’99-2003 use the same failure-prone crush-donut factory up-pipe design that leaks exhaust into the valley within 100,000 miles. The conversion is the time to fix this permanently with mandrel-bent 304 stainless bellowed up-pipes — while the top of the engine is already apart.

What the Conversion Delivers — Beyond Just Bolt-On Airflow

The individual gains from each component stack — but the reason experienced early ’99 owners do this conversion isn’t any single number. It’s what happens when the whole top-side upgrades together:

• Access to the entire late ’99-2003 aftermarket: Once the truck is converted, every 7.3L performance part on the market fits — Stage 2 injectors, GTP38R ball-bearing turbo upgrades, S300 conversions, T4 pedestal swaps, chip programmers with proper late-99-2003 maps, aftermarket intake plumbing.
• Real airflow gain, not just cosmetic: The spider + plenum combination alone flows 18% more air than the factory late ’99-2003 intake, which itself already flows dramatically more than the early ’99 restrictive spider and 2″ plenums.
• The crush-donut leak is gone for good: 304 stainless bellowed up-pipes with flat-flange gaskets permanently fix the #1 exhaust leak on the 7.3L Powerstroke. The bellows absorb thermal expansion so the flange gaskets aren’t stressed cold-hot-cold.
• Boost control that actually works: The .84 A/R turbine housing on the late-style GTP38, paired with the correct wastegate actuator, gives predictable boost that doesn’t creep and doesn’t fall off. Combined with the ceramic-coated center section and turbine housing on the SL-100-007, EGTs drop noticeably under sustained load.
• Color-matched top end: Raw, Black, or Red options across the turbo compressor housing, spider, and plenums — the customer picks one finish and the entire visible top of the engine is coordinated.
• Solves the boot failure at the same time: The silicone spider-to-plenum boots eliminate the cracked/blown factory boot failure that leaks boost between spider and heads.
• Preserves the desirable early ’99 platform: Early ’99 trucks are more sought-after than late ’99-2003 in a lot of ways — forged rods (through 2000-2001), square-U-bolt front axle, the fender-mounted Powerstroke badge, the simpler air filter box, no intake air heater to fail. The conversion keeps everything the customer bought the early ’99 for and fixes only what needs fixing.

What’s Included

• SPOOLOGIC Stock Plus Performance Turbocharger SL-100-007 — brand new late-style GTP38 with 5+5 billet compressor wheel (60mm inducer × 80/84mm exducer, 5-axis CNC-machined forged billet aluminum), stock-size turbine shaft, .84 A/R turbine housing, factory-spec wastegate actuator, extreme duty journal bearings, 360-degree thrust bearing, step gap seal rings, VSR balanced, ceramic-coated turbine housing and center section, non-EBPV delete pedestal, outlet plate, and EBPV terminator plug included. Sized to cleanly support up to ~400-500 rwhp with proper tuning, fueling, and supporting mods, on top of the airflow gains from the rest of the kit. Compressor housing available in Raw, Black, or Red.
• SPOOLOGIC Intake Manifold Spider SL-430-001 — brand new A356-T6 aerospace-grade heat-treated aluminum spider (Y-collector) with MDV Multi-Directional Vane technology, four pre-machined 1/8″ NPT ports (for nitrous, boost reference, EGT/IAT probes, or methanol/water injection), all mounting hardware and brackets. Available in Raw, Black, or Red.
• SPOOLOGIC Intake Manifold Plenums SL-430-002 — pair of brand new CNC-machined 3″ aluminum plenums (one per cylinder head) with high-flow internal geometry. Bolts directly to the SL-430-001 spider. Available in Raw, Black, or Red.
• SPOOLOGIC Spider-to-Intake-Plenum Boots SL-420-003 — pair of reinforced silicone connector boots (late-style 4″ straight, not the early-style tapered boot) that seal the spider to each cylinder head plenum. Rated well beyond stock boost levels. Resistant to heat, pressure, fuel vapor, and oil. Worm-gear clamps included.
• SPOOLOGIC Heavy Duty 304SS High-Flow Bellowed Up-Pipe Kit SL-510-003 — mandrel-bent 304 stainless steel up-pipes with multi-layer bellowed expansion joints, ceramic-coated ductile iron Y-pipe collector, flat-flange design with new gaskets, TIG-welded flanges. Includes turbo pedestal O-rings, compressor housing O-ring, gaskets, and mounting bolts.

Color Selection — Raw, Black, or Red

The customer picks a single finish (Raw, Black, or Red) that is applied across the turbo compressor housing, intake spider, and intake plenums. All three parts ship matched to the selected color. The silicone boots ship in black regardless of color selection; the up-pipe kit ships in mandrel-bent 304 stainless with a ceramic-coated Y-pipe collector regardless of color selection.

• Raw — bare CNC-machined and cast aluminum. Shows the machining marks, the material, and the build quality.
• Black — the low-key look. Blends into the engine bay, hides fingerprints, complements a black-and-chrome truck or a work truck.
• Red — the show-truck finish. Pops against the black valve covers and intercooler pipes.

Installation Notes

• Conversion is a full top-side R&R — plan for a full day in the driveway with a helper, or a shop day if the truck is a daily driver. The intercooler and CAC pipes are removed to access the turbo and spider.
• Injectors, HPOP, and glow plug system stay in the truck — early ’99 AB-code injectors, the 15-degree HPOP, and the single glow plug relay are not touched by this conversion.
• Customers who want to run larger late-style injectors (AD-code 140cc or aftermarket stage injectors) will need to add the HPOP upgrade and tuning as a separate job.
• The early ’99 does not have a factory intake air heater (AIH). This does not need to be added — the late-style spider and plenums fit without AIH.
• Clean every mating surface before installing the new gaskets — the bellowed up-pipe flanges and turbo pedestal O-rings will not seal over carbon deposits or old gasket material. Razor scraper and brake clean is the minimum.
• The late-style pedestal, outlet plate, and EBPV terminator plug are included with the SL-100-007 turbo. No separate pedestal purchase required.

Features

• Complete early ’99 to late ’99-2003 top-side conversion kit — turbo, spider, plenums, boots, and up-pipes in one package
• Opens the entire late ’99-2003 7.3L aftermarket to the truck — every performance part fits after the conversion
• 18% airflow gain from spider + plenums over the factory late ’99-2003 intake, dramatically more over the restrictive early ’99 top end
• Late-style GTP38 with 5+5 billet compressor wheel, .84 A/R turbine housing, ceramic-coated center section and turbine housing
• 3″ plenums replace the 2″ early ’99 plenums — single biggest airflow bottleneck on the early ’99 top end is eliminated
• Straight 4″ silicone boots replace the failure-prone tapered rubber early ’99 boots
• Mandrel-bent 304 stainless bellowed up-pipes permanently fix the factory crush-donut exhaust leak — done at the same time as the intake, no second job later
• Raw, Black, or Red finish across the turbo compressor housing, spider, and plenums — color-matched top end
• Late-style non-EBPV delete pedestal, outlet plate, and terminator plug included with the turbo
• All components built brand new, never remanufactured
• No core charge on any component

Early ’99 identification — any one of these confirms an early ’99 truck:

• Engine build date 12/07/1998 or earlier (check the driver-side valve cover sticker)
• Engine serial number in the range 661,973 – 896,812
• Powerstroke fender badge (ahead of the front wheel arch) — late ’99-2003 has a longer Powerstroke door badge instead
• 4-bolt compressor housing on the factory turbo — late ’99-2003 uses a 5-bolt housing
• 2″ intake plenums with tapered spider-to-plenum boots — late ’99-2003 uses 3″ plenums with straight 4″ boots
• No intake air heater (AIH) on the intake spider — late ’99-2003 has a factory AIH (except California trucks)
• Single glow plug relay on the passenger-side valve cover — late ’99-2003 has two relays side-by-side (glow plug + AIH)

Turbo Applications

• Factory turbo removed: Early ’99 GTP38 (4-bolt compressor housing, small pedestal)
• Installed turbo: Late-style GTP38 (SPOOLOGIC SL-100-007) with 5+5 billet compressor wheel, .84 A/R turbine housing, non-EBPV delete pedestal

OEM Cross-References — Turbo (SL-100-007)

• Ford: 1831383C92, 1831383C93, 1831383C94, 1831450C91, 1831450C92, 1831450C93
• International: 1831383C91, 1831450C91
• Garrett: 702012-0001, 702012-0003, 702012-0010, 702012-5010S, 702012-5012S
• Ford service: F4TZ-6N653-A, F4TZ-6N653-B, F81Z-6K682-BARM, F81Z-6K682-CARM, F81Z-9E436-AA
• Cross-reference: TC-12-RM / TC12RM

OEM Cross-References — Up-Pipes (SL-510-003)

• F4TZ-6K854-C / F4TZ6K854C
• F4TZ-6N653-A / F4TZ6N653A
• F4TZ-6N653-B / F4TZ6N653B
• F81Z-6K854-EA / F81Z6K854EA
• F81Z-6K854-FA
• F81Z-9E436-AA / F81Z9E436AA
• W300006, W300013, W300050

OEM Cross-References — Boots (SL-420-003)

• F4TZ-8287-A / F4TZ8287A
• YC3Z-6C640-PA / YC3Z6C640PA

Fits 1999 7.3L Powerstroke

• Early 1999 Ford F-250 / F-350 / F-450 / F-550 Super Duty 7.3L Powerstroke
• Engine Build Date: 12/7/1998 and Before

⚠ Not For Sale In California

Emissions Notice: Not CARB approved. Not legal for sale or use in the state of California.

1-Year Limited Warranty

Every SPOOLOGIC component in this conversion kit is covered by a 1-Year Limited Warranty against defects in materials and workmanship from the date of purchase. Warranty coverage requires that the unit first be shipped back to SPOOLOGIC for inspection. If SPOOLOGIC determines the failure was caused by a defect in materials or workmanship, the affected component will be repaired or replaced at SPOOLOGIC’s discretion. Warranty does not cover labor, towing, downtime, consequential damages, failures caused by improper installation, failures caused by dirty or damaged mating surfaces, failures caused by tuning or modifications beyond the scope of this kit, or use outside the listed fitment.