MSD 83647 Heat HEI Ignition Module
Click image to enlarge
Q & A
What's in the Box
This all new Heat HEI Module supersedes the current PN 83645. Using upgraded components, the HEAT produces high output for stock and MSD applications plus has a built-in rev limiter that is more accurate and easier to set with the engine running.
Works with non-computer controlled (4-Pin) HEI housings.
- Easily installs to non-computer controlled (4-Pin) HEI housings
- Built-in adjustable rev limiter can easily be set externally
- Advanced dwell control for improved high rpm output
- The Hottest HEI Module you buy-period!
- Produces an incredible 7.5 amps of juice!
- Adjust the rev limiter without removing the cap!
- Fits in stock HEI distributors
547-83647 Instructions (PDF)
MSD Tech Bulletin (PDF)
You may also be interested in:
MSD 8225 HEI High Performance Direct Replacement CoilMore Info
HEI Advance Curve KitMore Info
HEI External Timing Adjustment KnobMore Info
Taylor Cable 76240 8mm Spark Plug Wires-Solid Core-Under Headers-90 -RedMore Info
Moroso Spark Plug Wires, Over Valve Covers, HEI Cap Ends, Install-ReadyMore Info
MSD 5554 Street-Fire Spark Plug Wires Set, Small Block Chevy 350 HEIMore Info
MSD 8843 Spark Plug Wire Separators, Pro-ClampMore Info
Performance Distributors S12000 DUI Brass Terminal HEI Cap & Rotor KitMore Info
Accel 9018C GM HEI 75-86 Extreme 9000 Ceramic Plug Wires, Under ValveMore Info
MSD 8416 GM HEI Distributor Cap and RotorMore Info
Scott HEI Plug Wires w/ Coil Wire, 8.5mm - BlackMore Info
MSD 35599 8.5mm Spark Plug Wires Set, S/B Chevy HEI, Under HeadersMore Info
HEI owners now have a choice to replace their stock coil with the MSD High Energy Unitized Coil for GM HEI Distributors. This coil is a direct replacement of the stock coil. The coil features special low inductance, high temperature windings which charge faster to give you increased spark energy at higher rpm. The premium epoxy filled construction is designed to withstand harsh race applications as well as the wear and tear that daily usage dishes out, and still deliver more spark energy to the spark plugs.
- Direct performance replacement for GM HEI coil-in-cap distributors
- 70:1 turns ratio and lower primary resistance produce high voltage output
- Full power sparks to 9,000 RPM when used with 8364 MSD HEI Module
- Recommended for use with MSD HEI Module PN 8364
Modifies any GM HEI distributor with either clockwise or counterclockwise rotation and offers plenty of curve possibilities. Center plate eliminates overcentering of centrifugal weights. Comes complete with detailed instructions.
NOTE: Installation of this kit may alter emission levels.
This little jewel replaces the vacuum advance on an HEI distributor. This allows you to change the timing without having to loosen the distributor - just turn the knob.
Fits V8 engine HEI distributor only.
Taylor Cable’s 8mm Spiro-Pro Series outperforms the competition in both looks and performance at a price you can afford. Spiro-Pro is simply a top of the line high performance 8mm ignition wire and is an excellent choice for race only applications with it's solid wire core.
- High grade silicone over silicone resists temperatures up to 600°
- Color coordinated silicone boots add a touch of class
- HEI boots have "Professional Grips" for easy on/off installation
- Double spring locking spark plug terminals provide a firm grip
- Wire core for racing applications
- Use with magnetos and point style ignition systems (non electronic)
- Fully assembled
- Coil wire is 35" long and requires final assembly
If you have ever tried to put plug wires together yourself, you know how fustrating it can be. These pre-assembled Moroso 8mm spiral core wires are fiberglass reinforced with a silicone outer layer. Wires have 90° boots on both ends. Available in red or black for small block Chevy.
- 90 Degree boots on both ends
- Over the valve cover wire route
- HEI distributor cap ends
- Designed for small block Chevy
- Coil wire not included
Note: HEI type sets do not include remote coil wire
Street Fire low resistance spark plug wires feature a low resistance conductor that’s wrapped in a sleek and durable black sleeve. The terminals are covered in black boots that protect the conductor from engine heat to ensure spark delivery. Street Fire spark plug wires have the quality you've come to expect from MSD Ignition at a price that's comparable to other brands. They feature spiral-wound, low-resistance conductors and high EMI suppression capabilities, with 90 degree boots.
- Long enough to go over valve covers
- Helically wound conductor suppresses electro and radio noise
- Kevlar core combination for great strength and durability
- Heavy duty terminals for secure connection
- 8mm silicone and synthetic jacket resists heat and abrasion
- 500 ohms per foot resistance for improved spark delivery and power
- Silicone boots protect against high exhaust temps
Separate your plug wires to keep them from arcing across one another with these MSD Pro-Clamp wire separators.
Set is supplied with two 4-wire, two 3-wire, and four 2-wire separators.
Don't cheat your engine out of any firepower available! This kit offers up to 50% higher dielectric strength and can handle all the voltage available with 100% brass terminals for maximum conductivity.
- Improved well design in the rotor eliminates burn-through
- Made from THE ideal resin for HEI cap and rotor design
- Nylon rotor screws eliminate a "ground" for the voltage to jump at high RPM
Accel offers the cure for burnt spark plug wire boots with the Extreme 9000 Series Ceramic spark plug wire set. These 8mm spiral core spark plug wires have ceramic boots on the spark plug end of the wires which makes it impossible to melt or burn boots. If you are running headers with close tolerances, have an engine bay with little room or an RV with boots that melt because of heat, these wire kits are the answer for burnt and melting boots.
- 8mm Ferro-Spiral EMI/RFI supression core
- 500 Ohms/ft resistance
- Ceramic boots will withstand 2000° F
- Stainless terminals
- For 1975-86 GM small block V8 HEI (under valve covers)
Ceramic Wire Core Cut-A-Way (Link)
The cap and rotor of any ignition system must be considered maintenance items. Just as you change the oil and filter of your car, you should always replace the cap and rotor as a set. To make things easy, we now offer these Cap and Rotor Replacement Kits
Scott Performance spark plug wires feature high-temp silicone plug boots with each cylinder numbered. Stainless steel spark plug terminals connect to wire-wound suppression cores, all wrapped in a 8.5mm silicone jacket. Wires are factory terminated for easy installation.
- Fits S/B Chevy engine (under headers)
- 8.5mm HEI Style
- Comes with coil wire
- Available in Red or Black
What makes or breaks a plug wire is not only how well the wire is insulated, but how low of resistance the center core has. These assembled wire sets test 40-50 ohms per foot, while most others test 1500 ohms per foot.
These low resistance spark plug wires are designed for Small Block Chevys with HEI and are routed under the headers.
Learn how to properly attach new spark plug terminals and boots by reading our tech article. How to Install Spark Plug Wire Ends.