You cant believe everything you read, ESPECIALLY on the internet! I know there is a lot of false information out there and as soon as one person starts it and it multiplies like a virus there isnt anything you can do about it but know the real deal for yourself. Those ID tag charts are correct from GM. I have heard all sorts of rumors and stories about lots of makes and models of transmissions since I have been in the business and it just leaves me scratching or shaking my head because I see so many different models come through, Im not talking just GM here this is true for all makes, import or domestic. A lot of the Bonneville forums mention a 4T60E-HD in their 92-95 series 1 supercharged 3800 but they arent. There were a lot of revisions made to the 4T60E during its run but the only HD version was for 96 in the series 2 L67 cars, HD labeling for the larger stronger differential and associated internal parts to accomodate it in that trans. One thing that may be mistaken or read the wrong way is that the 4T60E is a "heavier duty" version of the older 4T60 trans which in stock form couldnt handle the power of the newer engines coming out.