I'm using an MSD 6AL with a 70's stock distributor with my 67 Chargers stock tach. Has worked great for the last 10 years. Not sure why yours would be different? I run the tack off the plug on the MSD box instead of the coil.


67 Charger 383 auto
75 Dodge CNT 800 CAT Diesel
2012 Ram Crew cab 5.7 4x4