Project Atlas SFA: Darren's 2005 Astro 2WD Reference Build

Planning-stage reference build

Darren’s 2005 Astro SFA conversion is a proposed program, not a completed build. Nothing on this page has been fabricated or road-tested. Treat every dimension, part number, wiring pin, and torque value as verify before fabrication unless it links to an identified source.

British Columbia road-legal design gate

The reference vehicle is registered in British Columbia. Under the Motor Vehicle Act Regulations Division 25:

Section 25.20 — a suspension height increased or decreased by more than 10 cm from OEM specification places the vehicle in the modified-vehicle division.
Section 25.21 — such a modified vehicle must not be driven, operated, parked, or left on a highway until it has been presented to a Designated Inspection Facility (DIF) and an approval certificate has been issued.
The current BC Vehicle Inspection Manual (2025) steering section states: “No vehicle shall be approved if any part of the steering mechanism shows signs of failure or has been heated or welded.”

Implication for this program: a heated, welded, sleeved, or improvised drag link is inspection-disqualifying — not merely discouraged. The steering solution must use purpose-built, non-heated / non-welded components, or an alternative configuration accepted in writing by a DIF familiar with modified vehicles.

Pre-purchase action: before ordering donor axles, steering components, or approving geometry, consult a BC Designated Inspection Facility experienced with modified vehicles and obtain written requirements where possible.

BC-specific regulatory information, not universal legal advice. Owners outside BC must verify their own jurisdiction.

Vehicle baseline

2005 Chevrolet Astro Cargo Van
RWD / 2WD · 4.3L V6 (Vortec) · 4L60E
Front suspension architecture: coil-spring IFS (2WD/RWD). No torsion bars on this reference van.
Jurisdiction: British Columbia, Canada — modified-vehicle inspection applies.

Confirmed modifications currently on the van

Journey's Off Road 5-inch suspension lift
3-inch body lift
BFGoodrich KO2 tires (size not yet recorded in Atlas)
Eaton Detroit Truetrac rear differential
New rear leaf packs with overload helpers
External transmission cooler
140A alternator
Smittybilt 10,000 lb winch
Expedition / camper build

Baseline data not yet captured

Front tire size and stamped load rating
Rear axle final ratio
Curb weight (front / rear / total) — never measured on a scale
Payload as currently loaded
Frame rail measured height and width at multiple stations

Objectives

Preserve daily-driver usability on pavement.
Support the existing expedition/camper build weight.
Add meaningful front articulation without compromising highway stability.
Retain ABS and safety systems.

Open engineering decisions

Decision	Status
Final donor axle & WMS width	Open — pending measurement of frame and wheel/tire package.
Transfer case model & spline config	Open — pending donor availability and 4L60E output verification.
Steering box selection	Open — pending mission profile and tire diameter.
Spring family & rate	Open — pending sprung-weight measurement (van has not been on a scale).
Gear ratio	Open — pending final tire diameter and cruise RPM target.

Rejected ideas & reasons

Idea	Reason for rejection
Welded 'bent' OEM drag link to clear differential	Not standard practice. Safety-critical failure mode.
Delete ABS to simplify wiring	Legal/insurance implications; documented safety loss.
Reuse random 1970s GM leaf packs without rate calculation	Rate/arch not matched to sprung weight; axle wrap and geometry risk.

Decision log (seeded)

[TBD] Program initiated as planning-stage effort. Reference vehicle baseline recorded.
[TBD] Measurement Workbook opened; awaiting first physical measurement session.
[TBD] Decision guide completed; alternatives compared.

Budget status

Use the budget worksheet to enter real quotes. No dollar totals are claimed here until quotes are in hand.

Photos

Photo placeholders — nothing has been photographed for this program yet. This section will populate as the mock-up, teardown, welding, and shakedown phases produce evidence.

Lessons learned

To be added as the program progresses.

What we know

• Baseline vehicle and existing modifications listed above.

Proposed design targets

• All engineering decisions above are planning-stage proposals only.

Must be verified before fabrication

• Everything else — see 'Open engineering decisions'.

Verified sources

Tier 1 — OEM / regulatorBC Motor Vehicle Act Regulations — Division 25 (§25.20 / §25.21)
Tier 1 — OEM / regulatorBC Vehicle Inspection Manual (2025)
Tier 3 — vendor / catalogGM Parts Giant — 2005 Astro 2WD front suspension (coil-spring architecture)