Dual alternator plate for GM V-8 and V-6 engines with this drivers side air conditioner mount serpentine belt. Actual plate picture not shown.  Fits most 1999 to present. V-8 and V6  engines with the drivers side A/C pump mount.  This version is for engines with an integrated Power Steering mount tank with a cap.  Check your engine to see if you have a steel engine lift ring similar as shown in the upper right (rear) of the picture except it will not have the two tapped holes as shown if will have an oval hole in a steel lift ring - and is not cast.  PLATE ONLY -  (the black part in the front of the upper picture) you will need to source the idler pulley and other parts - a bone yard will do fine for the pulley and spare alternator often.  A CS-144 alternator will also fit with the same mounting holes.   GM wiring schematic diagram  and parts list is included - including recommended belt size.  No alternator mount hole spacers welded on - washers instead. 

 This is based on a replica with no alternator mount hole spacers welded on - use washers or a 1/2-13 plain nut instead. You will need space the diameter of the alternator you will use next to the power steering pump, as is there on most vans and vehicles with a v6 or v8 engine and you may need to gently bent the power steering line tubing to clear it.  A hand held tubing bender from Harborfreight to bend it on the engine without removing the line.  Uses the engine lift ring as a rear support point..  This is considered a custom order item and is not returnable.  Custom Made Item Not Refundable or Returnable

This mounts the alternator just above the and to the side of the power steering pump.  If you have a VAN or remote mount power steering fluid tank with a hose running to it order this one instead => https://bigbay4bestbuys.com/GM_V8_and_V6_dual_alt_plate_for_VANS  See that page above for more info on alternators sizes and what fits, how to upgrade and covnert the alterantors and why.

GM never made a factory dual alternator option fo the gas engine as far as is known, this is an aftermarket solution

You need dual alternators if you have a high amp stereo or  to run any decent sized Hydrogen Generator system and the pump required to feed it at idle as a single alternator will not put out enough amps - even a high amp one