THIS MOUNT IS DESIGNED TO REPLACE THE ORIGINAL FENDER MOUNTED BRACKET ON ALL 96-00 GMT400 VEHICLES AND ALLOWS SECURE MOUNTING OF YOU GEN 4 E38 OR E67 ECM. THESE BRACKETS COME IN 2 OPTIONS ONE FOR 6 SPEED AND ONE FOR 4 SPEED TRANSMISSIONS. 4 SPEED TRANSMISSIONS HAVE TCM MOUNTING LOCATION UNDERNEATH BRACKET. ATTACHES TO FACTORY FENDER AND ABS BRACKET MOUNTING POINTS.