Yes the I is probably a 1 so it was assembled on Jan 6th. Also the 1966 327 with the powerglide and a Rochester carb has a "HCR" suffix. It shows this as a 327 275HP. I would check a few things. Get the casting number and casting date from the rear of the engine. These can identify the year in most cases. Also check the build date of your car on the cowl tag to see if it is in line with the Jan build date of the engine.