Here we have an OTC 7639. Here's the complete set for servicing seized disc-brake rear-caliper slides on GM W-body cars.
OTC 6686 GM Northstar V8 Cam Tool Kit
OTC 6616 GM Water Pump Holding Tool EcoTech 2.2L 2.4L New
CTA Tools 7639 Ford Valve Spring Compressor - 4.6L, 5.4L & 6.8L 3V
SK TOOLS 7639 RETAINING RING PLIERS INTERNAL/EXTERNAL
OTC Tools 6706 GM Injector Rail Assembly Remover
System Memory Cartridge 1981-87 GM OTC SYSTEM 2000
