I just got a 1998 GMC Suburban 2500, 4X4, 7.4 trying to get it back on it's feet, there is a box attached to the driver side battery mount, it evidently had some tubing attached to it but that is all gone, anyone know what this is and is it necessary? I'm going to need lots of help getting this one going, have ordered new water pump, power steering pump, all new PS and WP hoses and am now trying to figure out the ignition wiring, got it running but thinking will need more attention, gotta get it ready for the trip up the Alcan to the Great Land, thanks to all, Patrick