Is a 1996 Chevy 1500 transmission compatible with 1994 GMC Sonoma?

No, a 1996 Chevy 1500 transmission is not directly compatible with a 1994 GMC Sonoma. While both are GM vehicles, the transmissions used varied significantly by year and even engine type. The bolt patterns, input shaft lengths, and other critical dimensions are likely different, preventing a direct swap. You would need an extensive adaptation, which is usually not practical or cost-effective.