OK I think you are talking about the truck receiver. The part in the back of the truck that bolts to the frame and has a 2” sq pin box hole.
The hitch part plugs in the receiver.
Now where to get a receiver. This is actually not hard at all.
Here are 2 places I have bought receivers from and had good luck.
Southwest wheel. They sell Putnam receivers and they are very good. http://www.trailerpart.com/hitchguide.htm
I do not know the year model of your truck or I would of looked it up.
Etrailer. They sell Reese and Drawtite. Both good. http://www.etrailer.com/fitguide.htm
There are a lot of other good on line places, just these 2 I have bought from and had good service. Once you find the brand and part number you want, then web searching can save some $$.
Since you are looking, look for a Class 4 (IV) receiver. It will handle the full rating of your truck unless you have a 2500 HD then maybe need a class 5 but the Class 4 will still do most of your towing jobs. The class 4 also is a weight distributing rated receiver that you will need once you load up the camper. .
The receiver install is straight forward and just a bolt on. However getting the 7 wire plug hooked up with a brake controller will actually take you more time. But all can be accomplished if you are handy and have some basic hand tools.
Do you have a brake controller yet? And a heads up on it. Do NOT get a time based brake controller. For a few dollars more you can get a proportinal braek controller that far out performs the time based ones. A popular brand is the Priodgy. It sells for around $100 maybe more pending sales.
Also does your truck has a aux transmission oil cooler? If you do not know we can help you search that out too. GM has RPO codes in the glove box that tells all.
And next is a weight distributing hitch. I looked up your camper.
A 1987 T2153 came from Sunline, 21 ‘ 10” long, weighs 3,115# empty, has a 4,480# GVWR and has a dry unloaded tongue weight of 345#.
You are on the edge of needing a WD hitch. And if you actually put much gear in the truck bed behind the rear axle, you will need one. You will aslo need a sway control system.
Do you have a WD hitch yet?
Hope this helps
Current Sunlines: 2004 T310SR, 2004 T1950, 2004 T2475, 2007 T2499, 2004 T317SR
Prior Sunlines: 2004 T2499 - Fern Blue
2005 Ford F350 Lariat, 6.8L V10 W/ 4.10 rear axle, CC, Short Bed, SRW. Reese HP trunnion bar hitch W/ HP DC
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