ECT sensor wiring for gauge with black box removed?

[shmiet]

How do I wire the ECT sensor to my gauge if I'm removing the black box? Do I remove the double pinned ECT sensor from the neck at the front of the engine and remove it from the harness? Then use the single wire one located on the driver side of the block?

And can i use #13 BRN wire on the black connector(98 black box) in place of the LS blue #19 or #75?

Any help is greatly appreciated.

Thanks, Kevin

Truck is 98 GMC doing LM7 swap.