No GMT360 got a 4L65E. All 4.2 and 5.3s got the 4L60E regardless of year, the SS/Aero got the 4L70E. The 70E is a slightly upgraded 65E which is a better unit than the 60E. I dont think the 60Es ever got the 5 planetary gears, but I could be wrong.
If you dont want to buy a used 60E for like $500 shipped of eBay or Craigslist and want a new one, might as well buy a built unit from a reputable trans builder like RPM Transmissions, Phoenix Transmission, or FLT. Be much cheaper than a factory new unit and have better parts. If your core is still good, usually you can either have it rebuilt or send it to one of the aforementioned shops for a core charge.
FLT has a stage 3 Street Performance 4L60E for $1595 after core exchange, pretty good deal for a mildly built 60E that has some 65E upgrades, Vette servo, and set to FLT specs.
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