Arco DC001 Distributor Cap – MerCruiser / Volvo Penta GM V8 Thunderbolt IV & V HEI
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Arco DC001 Distributor Cap – GM V8 Thunderbolt IV & V HEI Ignition
Keep your GM V8 inboard firing on all cylinders with this direct-fit replacement distributor cap from Arco. Built to OEM specifications for MerCruiser, Volvo Penta, Pleasurecraft, and Indmar applications equipped with Thunderbolt IV and V HEI ignition systems, this cap delivers reliable spark distribution and corrosion resistance in demanding marine conditions — making it a smart choice for seasonal tune-ups or replacing a cracked, worn, or carbon-tracked cap.
Compatible Applications
- MerCruiser GM V8 engines with Thunderbolt IV & V HEI ignition systems
- Volvo Penta inboard engines (replaces OEM 3858975)
- Pleasurecraft inboard engines (replaces OEM RA108009)
- Indmar inboard engines (replaces OEM 556345)
OEM Cross-Reference
- MerCruiser: 16457A4, 43557, 43557A1, 805759A2, 805759A5, 805759T1, 805759T2, 90746A1
- Volvo Penta: 3858975
- Pleasurecraft: RA108009
- Indmar: 556345
- Sierra: 18-5395
Specifications
- Part Number: 57-DC001
- Ignition Type: Thunderbolt IV & V HEI (GM V8)
- Condition: New
Complete Your Ignition Service
For best results, replace the distributor cap and rotor together. Pair this cap with the Arco DR002 Distributor Rotor – MerCruiser / Volvo Penta MPI or the Arco DR003 Distributor Rotor – MerCruiser / Volvo Penta / OMC V8. If your engine uses a coil-in-cap HEI system, also consider the Arco IG008 Ignition Coil – MerCruiser V8 Delco HEI. Browse our full Ignition Components collection for spark plugs, wire sets, and more.
Parts Desk Insights
The DC001 is the right cap for GM V8 inboards running Thunderbolt IV or V HEI ignition — one of the most common ignition configurations found in MerCruiser sterndrives and inboards from the late 1980s through the mid-2000s. It’s the go-to replacement when an engine is showing hard-start, misfire, or rough idle symptoms and the cap shows visible cracks, carbon tracking, or corroded terminals. Always replace the rotor at the same time — caps and rotors wear together and should be serviced as a pair. Confirm your engine’s ignition type (Thunderbolt IV vs. V) before ordering, as cap fitment varies between HEI generations.
Shipping information
In-stock and OEM parts: ship same or next business day.
Locally warehoused items: ship within 1-3 business days.
Special-order items: timeline confirmed after order.
Returns & warranty
Returns & Satisfaction Guarantee
We stand firmly behind the quality of every product we sell. Your confidence matters to us — and we back it with a straightforward 30-Day Satisfaction Guarantee.
If you are not fully satisfied, you may request a return within 30 days of delivery. All returns must receive pre-approval prior to being sent back. Unauthorized returns will not be accepted.
To qualify for a return:
Item must be in new, unused condition
Product must be in its original packaging
All parts, components, hardware, manuals, and accessories must be included
Packaging must be undamaged and suitable for resale
Important:
Electronics are strictly inspected. No returns on open-box electronics. Exceptions may apply only with prior written approval. Any electronic unit that has been installed, powered, activated, or altered may not be eligible for return.
We are serious about product integrity — and equally serious about taking care of our customers. If there is ever a product issue, contact us immediately so we can make it right.
For return authorization, please contact our support team before shipping anything back.