Got this in the mail yesterday:
It is an actual LT4 part from the passenger side auxiliary radiator (outside connection) to the main radiator on the right side. My LT4 conversion kit came with a plastic 90 degree in conjunction with a portion of the LT1 hose to do the same connection.
This will eliminate one hose clamp/plastic adapter of the system. Likely not an issue, but when I performed the install - this juncture leaked - I probably did not tighten it properly.
My logging loops were returning 15 mpg. I won't complain about the fuel consumption...I think quite good for touching 160 mph how many times and 650 HP.