Found out myself. Feed and return lines are 5/16", vent line is 1/4"

The red wire always attaches to pin 1 of both the hard drive and the controller or motherboard.

The red line is usually closer to the power connector. However, older hard drives did not follow this convention. There might not even be a specification for this. To be sure, look closely at the hard drive for a distinguishing mark on one end of the connector, such as a "1" or triangle indicating which end the red line should be.

It's easy. Use 1/2 PEX line to back of fridge, install s/o valve with a take-off to fridge( usually 1/8 flex line)

ABOUT CENTER TO THE CARBERATOR YOU WILL SEE A HARD LINE (FUEL LINE) SMALL LINE SCREWED INTO LARGER FITTING BEHIND THE LARGER FITTING THERE IS A SMALL 1 1/4 INCH FUEL FILTER INSIDE OF LARGER FITTING

Yes, hard but supple. There is a fine line there.