I posted this in the 73-79 forum and got no response so thought I would try here. I have an Autolite 2100 with 1.23 cast into the side of the bowl but there are also the letters "TR" cast directly below the 1.23, all inside the circle cast into the side of the carb. Real curious if anyone out there knows what this TR might stand for, as I have never seen this before. No tag on carb, front left drivers side leg has 9T-J stamped into it which I believe points to a 1969 year of production, and from what I can gather was used on the 360 and 390 engines. Any info would be greatly appreciated!