I know they stepped it up to the 4t65 in 1997 but i also know that the 4t60-e was also installed with the 4.9 V8 in the Devilles. So is it A strong tranny or not? Weak links? I know there was also a 4t60e HD that was used with the supercharged motors. Are they basically the same but the HD has beefier interior parts and a differant torque converter? can a 4t60-e be converted to a 4t60-e HD?

97 is the pivot year for the 60 65 transition. 97 N/a still have 60'* and boosted guys have the 65-HD. In 98 all 3.8 bonne'* had 65'* non-HD for na and HD for charged. 65 are superior for the most part because of the 9 vane pump in the 65 as compared to the 7 in 60'*.
As for difference in non-hd to HD the difference is the differential and housing plus a different passenger side axle. TO upgrade the 60 is a little more involved but upgrading a 65 is pretty simple. If you are going to go HD I'd spend a little more time and money and get yourself a 98+ 4t65e-HD for a H body.

bump.....

If you want to upgrade your '60 to a '65, you may need to fabricate a couple of custom mounts. More importantly, you'll need to do something to your PCM, as something vacuum-operated on the '60 is computer-controlled on the '65.

I'm not sure if it'* doable.

oh it'* doable