For those who install a Turbo-350 transmissions (or other transmission with
no reluctor ring) into 1989 and newer trucks, the differential mounted 40-tooth
reluctor-ring kit is a simple solution to make the electric-speedometer, cruise-control,
and anti-lock brakes work.
The complete installation of the differential-mounted 40-tooth reluctor-ring
normally takes less than an hour. Click the following link to download
complete Installation Instructions. (Adobe
Acrobat .pdf if you need the free Acrobat Reader, go
The 40-tooth reluctor-ring (shown above) bolts to the differential pinion flange.
The reluctor-ring is made of two halves, so that it can be installed without
removing the pinion flange.
The vehicle-speed-sensor (GM part #15547452) shown is used on transfer cases
of 1989 and newer S-10 truck, AWD Astro Vans, and 1987 and newer full-size 4X4
trucks. The part is readily available at most wrecking yards for a $10$20,
although retail cost is about $80, and we sell them new for $50 including shipping.
The vehicle-speed-sensor is mounted to a bracket (prototype shown) that bolts
to the differential webbing. Two 1/4" holes need to be drilled into the
differential webbing to mount the bracket.
Flexible twisted-pair wiring connects the VSS to the engine wiring harness.
The differential-mounted reluctor-ring kit for a 7-1/2" or 7-5/8"
rear end is Stealth Conversions Part # 4L60-006 and cost is $80, including shipping.
On differentials with a pinion-flange harmonic-dampener, the pinion flange will
have to be replaced with a standard style pinion-flange as shown above.