Those are the mechanical constraints / differences. Thanks for the insight.
Are they electrically equivalent… same sensors, valves, solenoid(s), even so much as to having the same electrical connector, thus allowing the LS ECU harness to be plug-n-play with the older (OP’s 1998) 4L60E… or not?
If you can get around the mechanical constraints/parts' fitment incompatibility issues, all of the command and control functions were identical for the most part from
1996-early 2006 (a slight redesign of the PWM TCC reg valve took place starting in 2001-no changes to solenoids though)...
Late 2006-2008 were different (ISS introduced) and
2009+ is completely different (Internal Mode Switch introduced; MLPS, 3-2 solenoid, PSM all eliminated)...
1993-1994 are interchangeable/the same and
1995 is a stand-alone year (first year of the PWM TCC apply strategy)...Those are all of the 4L60Es 'vintages' throughout its lifecycle from a command and control standpoint.
Command and control = PCM's trans control programming/logic, electrical/electronic components, valve body, pump hydraulics, separator plate, accumulator configuration.
I've built 700R4s for LS swaps in the past so there has to be some kits or adaptive methods used by these folks to run those transmissions behind LSX engines...But I only do bench/carry out builds, never see the vehicles the customer installs the transmission into so am not up on all the available kits or approaches folks use for these swaps.