New 24 Volt Waterproof Spark Plug Adapter - 24VSPA-1
Vintage Power Wagons
$2200$22.00
Shielded Spark Plug Adapter Kit (2243 Spark Plug Adaptor Kit) – For 24V Military Ignition Cables Correct fit for Dodge M-Series, Jeep M38/M38A1, and other 24V waterproof systems.
This adapter kit allows you to retain your original 24V military waterproof ignition cables while switching to our modern SP24-NS spark plug. Unlike generic adapters, this kit is specifically designed to work only with the SP24-NS plug. Other plugs will not seat or seal correctly and may cause misfires or poor performance.
Kit Includes: • 1x PEET High-Temp Plastic Threaded Adapter (interfaces with SP24-NS and 24V military cable ends) • 1x Brass Insert Plug (positions spark plug tip correctly and supports proper heat range and ignition performance)
Military vehicles like the Dodge M37 and Jeep M38 use 24V shielded ignition cables that screw onto large military-style spark plugs (e.g., Autolite 2245 or 2243), which are becoming increasingly hard to find.
This adapter threads directly onto our SP24-NS spark plug (14mm x 1.25 thread), allowing it to interface with the original 5/8"-24 threaded cable ends. It preserves the waterproof and radio-suppressed design of your original 24V system.
Important Compatibility Note: This adapter only works with our SP24-NS spark plug. Other 14mm plugs do not have the correct shoulder, reach, or sealing geometry and will cause performance issues.
Installation Instructions:
Use Only the SP24-NS Spark Plug – This adapter is precision-designed to match the dimensions of the SP24-NS plug. Do not substitute.
Insert the Brass Plug – Drop the included brass insert into the adapter.
Thread the Adapter Onto the Plug – Carefully screw the adapter onto the SP24-NS spark plug until snug. Do not overtighten.
Install the Assembly in the Engine – Thread the assembled unit into your cylinder head like a standard 14mm plug. Torque to spec: 18–21 ft-lbs for aluminum heads, 25–30 ft-lbs for iron heads.
Attach the Military Ignition Cable – Thread the 24V waterproof cable end onto the external 5/8"-24 threads of the adapter to complete the sealed and shielded connection.
Compatible Vehicles:
Dodge G740 / G741 Series (M37, M43, M601, etc.)
Jeep M38, M38A1
Other vintage military vehicles using 24V shielded ignition cables
Why Use This Kit?
Retains your original 24V waterproof ignition system
Eliminates the need to find rare 18mm military spark plugs
Uses a currently available SP24-NS spark plug that fits, seals, and performs correctly
Maintains proper compression, ignition timing, and waterproof shielding
Note: Shipping is not included in the product price and will be calculated once your order is received.
Related Items
choosing a selection results in a full page refresh
