Down to the last couple wires on swap... need help

[Kardain]

Ok, here goes... I have a 97 Sunfire w/ a 3400 from a 2001 Grand Am under the hood. After pouring through SI comparing schematics and whatnot, I have 2 last questions that maybe someone can answer.

1) The PCM/ECM pinout shows C1-55 as the Vehicle Speed Signal. I'm assuming this is the wire that goes to the speedo on the ICM? Also is that the one that is 4000 ppm output?

2) I have an aftermarket fan controller (SPAL) that has its own 2-wire sensor to trip the fans on and off rather than use the stock wiring. This will eliminate the need to recalibrate the controller if the battery is disconnected. Apparently somewhere on the firewall side of the block there is a coolant passage that can be used for this sensor. Anyone know where exactly this coolant passage is located? I don't want to pull the rear head to drill/tap...