There are a couple of important differences between the LT1-era TA seats, and the LS1-era TA seats. (these are the AQ9 seats)

LT1 seats

-power lumbar only
-manual adjust for front/back, under thigh bolster, rake
-no up/down adustablity
-sit lower in the car, as there is no bulky motor underneath
-large headrest, that often will not stay in place, due to broken part inside
-available in beige or medium grey (graphite) leather, or cloth

LS1 seats

-power lumbar
-power adjust for front/back, up/down, rake
-no under thigh adjustability (panel is fixed in place, does not move)
-sit higher in the car, due to motor underneath
-small headrest, moves up and down only, not forward and backward
-available in beige, taupe, medium grey (graphite) or dark grey (ebony) or cloth

Ive had both seats, and actually prefer the LT1 era seats for the following reasons:

-under thigh bolster is moveable
-seats sit lower in the car, giving you more headroom
-large headrests (if they aren't broken) move forward and back, plus up/down

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1999 TA Firehawk #C08, M6 blk coupe
All GM options, all SLP options, lots of aftermarket stuff
Newest addition: fresh paint, new decals

 

Man i wish i knew what it took to fix the head rests. My big headrests have always been floppy.