The 1966 Daimler Sovereign has 8 ignition parts with verified fitment on this page — 1 part type and 5 brands, covering the 4.2L L6 engine. Each part includes a manufacturer part number and application notes.
On the 1966 Daimler Sovereign, the ignition system delivers spark at the right moment — plugs, coils, wires, distributors and ignition modules. Every listed part is a Spark Plug.
Every part on this page is matched to the 4.2L L6 — the only engine offered in the 1966 Daimler Sovereign.
The most listed brands for 1966 Daimler Sovereign ignition parts are CHAMPION (3 parts), AUTOLITE (2 parts) and ACDELCO (1 part), plus 2 more brands. Quality grades include Copper / Nickel, Iridium and Double Platinum.
2 parts on this 1966 Daimler Sovereign page carry a "Popular" badge — the source catalog's flag for options frequently chosen for this vehicle — including ACDELCO R43XLS (Spark Plug) and AUTOLITE XP64 (Spark Plug). Click any part number to see every vehicle that part fits.
Spark Plug
Summary: Notes include pre-set gaps of 0.025", 0.030" and 0.044". Replacement brands in this table include CHAMPION, AUTOLITE and ACDELCO.
Copper / Nickel
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| ACDELCO Popular | R43XLS | 🇺🇸 US 🇨🇦 CA | ProfessionalConventional | View on Amazon |
| CHAMPION | 315 | 🇺🇸 US | Copper PlusPre-Set Gap: 0.025" | View on Amazon |
| CHAMPION | 332 | 🇺🇸 US | Copper PlusPre-Set Gap: 0.025" | View on Amazon |
| CHAMPION | 3321 | 🇺🇸 US | Copper Plus | View on Amazon |
| MOTORCRAFT | SP436AX | 🇺🇸 US | Copper | View on Amazon |
Double Platinum (lasts up to 3x longer than Copper / Nickel)
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| AUTOLITE | APP64 | 🇺🇸 US | Double PlatinumHex Size: 13/16 In | View on Amazon |
Iridium (lasts up to 4x longer than Copper / Nickel)
| Brand | Part Number | Markets | Notes | Buy |
|---|---|---|---|---|
| AUTOLITE Popular | XP64 | 🇺🇸 US | Display PackQTY2 | View on Amazon |
| SKP | SP1042 | 🇺🇸 US | Tapered Ground Electrode with Platinum Chip | View on Amazon |
This table covers the spark plugs for this engine. Typical signs include misfire under load, rough idle, or a flashing check-engine light. Verify the gap even on pre-gapped plugs, and replace coil boots that come off a high-mileage engine.
8 Spark Plug parts for the 1966 Daimler Sovereign come from 5 brands — CHAMPION, AUTOLITE, ACDELCO and 2 other brands. The "Popular" part is ACDELCO R43XLS.
The Copper / Nickel section lists 5 options from CHAMPION, ACDELCO and MOTORCRAFT — grouped under the catalog's "Copper / Nickel" designation — the notes column spells out what sets them apart. ACDELCO R43XLS is listed in this group.
The Double Platinum (lasts up to 3x longer than Copper / Nickel) section lists 1 option from AUTOLITE — grouped under the catalog's "Double Platinum (lasts up to 3x longer than Copper / Nickel)" designation — the notes column spells out what sets them apart. AUTOLITE APP64 is listed in this group.
In the Iridium (lasts up to 4x longer than Copper / Nickel) grade, AUTOLITE and SKP supply 2 parts: grouped under the catalog's "Iridium (lasts up to 4x longer than Copper / Nickel)" designation — the notes column spells out what sets them apart. A representative part number is AUTOLITE XP64.
This group includes ACDELCO R43XLS, CHAMPION 315 and CHAMPION 332 and the remaining parts above.
Buying Ignition Parts for a 1966 Daimler Sovereign
On this vehicle, the ignition system delivers spark at the right moment — plugs, coils, wires, distributors and ignition modules.
- Confirm you have the 4.2L L6 engine — every part on this page is matched to it.
- Read the notes on each row for position, trim and spec qualifiers before you order.
- Where labor overlaps, replace plugs and wires (or coil boots) as a set — one weak cylinder makes the whole set feel bad.
- Cross-reference the manufacturer part number against your old part or a service-manual listing.
Start with the largest groups on this page: Spark Plug .
Frequently Asked Questions
How many ignition parts fit the 1966 Daimler Sovereign?
Our catalog currently lists 8 ignition parts for the 1966 Daimler Sovereign across 1 subcategory and 5 brands, covering the 4.2L L6 engine. Each part is matched to the engine(s) it fits.
What are the signs of ignition problems on a 1966 Daimler Sovereign?
Common symptoms include misfires under load, rough idle, flashing check-engine light, or poor starting in damp weather. If you notice any of these, identify the affected subcategory above and cross-reference the part numbers listed.
What spark-plug gap is listed for the 1966 Daimler Sovereign?
Notes on this page include pre-set gaps of 0.025", 0.030" and 0.044". Still verify against spec — even “pre-gapped” plugs should be checked before they go in.
What should I replace at the same time?
Where labor overlaps, replace plugs and wires (or coil boots) as a set — one weak cylinder makes the whole set feel bad.
What do the market flags (US, CA, MX) on each part mean?
They show the market for which the manufacturer published application data for that part — where the vehicle was first sold, not where the part was made. If your 1966 Daimler Sovereign was originally sold in the US, the safest choice is a part marked for the US market.
How do I make sure a part fits my 1966 Daimler Sovereign?
Every part on this page is matched to the 4.2L L6 engine. Then gap matters even on “pre-gapped” plugs — verify against spec, and replace coil boots when they come off a high-mileage engine. The notes column carries position and trim qualifiers where they apply.
Other Parts for the 1966 Daimler Sovereign
Ignition Parts for Other Daimler Sovereign Years
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