I worked on the first C-130's at Eglin AFB during their operational tests in 1956-1957. The radios were the common ARC-27 UHF comm. The VHF nav radios were the also common ARN-14's. Additionally, the radar was an APS-42, maybe with an upgraded banana peel antenna instead of the standard round dish antenna. Intercom was AIC-10.
During that era, comm and nav boxes were pretty standardized. Nearly everything flying had the same stuff then.
The ARN-14 drove an ID-249 and ID-250 in the instrument panel. There might be pictures of those floating around the internet.