69 340 Swinger question

Good evening all! I don't post a lot on here, but really enjoy reading all the articles I can. There is a ton of knowledge here, thanks for that! There's some far out stuff too! Haha
The question I have regards the 69 340 swinger. I have a true lm23p9b car, did they install the torque boxes to strengthen the chassis on this car? This car does not have them, my limited knowledge thought these cars came equipped with them. This car came with an auto, non 4 spd. TIA