The all new MSD 83647 Heat HEI Module supersedes the current PN 83645. Using upgraded components, the 83647 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.
The main difference between the two modules is that the 83647 adds a built in rev limiter that is programmed through the green tach output wire
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 and Aftermarket HEI Ready To Run distributors
Features
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