Hitch Receiver, drilling?

Everywhere place I check for a tow hitch reciever says I must drill into my chasis, but I have seen hitch recievers on my model/year trucks that show they bolt right on?

Little help on this, I don't want to drill or pay someone to drill and I have having a hard time finding a hitch reciever that claims to not require this.

....and every used hitch I find will only fit Ford, chevy, or dodge !!!!!

Take a look at these...

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200332913_200332913

you will have to search the links below for your specific vehicle...
But you don't have to drill holes.

http://www.hitchestogo.com/

http://www.partsamerica.com/ChangeZipCode.aspx?MfrCode=HOP&MfrPartNumber=43505&PartType=874&PTSet=A&DestinationPage=%2fProductDetail.aspx%3fMfrCode%3d HOP%26MfrPartNumber%3d43505%26PartType%3d874%26PTS et%3dA

Take a look at these...

http://www.northerntool.com/webapp/wcs/stores/servlet/product_6970_200332913_200332913

you will have to search the links below for your specific vehicle...
But you don't have to drill holes.

http://www.hitchestogo.com/

http://www.partsamerica.com/ChangeZipCode.aspx?MfrCode=HOP&MfrPartNumber=43505&PartType=874&PTSet=A&DestinationPage=%2fProductDetail.aspx%3fMfrCode%3d HOP%26MfrPartNumber%3d43505%26PartType%3d874%26PTS et%3dA

Those say "no drill" meaning you don't drill into the hitch, but when looking at the instructions, it says to drill a hole into your frame.

Ah.

On the hitches to go website... The only PDF I could open on my computer was (is?) the PDF for installation on 1987 - 1995 Pathfinder. (PDF 36152) which does not indicate drilling holes is necessary. Although it does note a 1/2" drill bit..?
(don't know why I couldn't get "Pickup truck" [PDF 75186] instructons to open)
So I presumed (evidently incorrectly) that the install would be the same for my 1993 pickup.
My bad.
I had saved those links from many months ago when I was considering putting a hitch on my truck but I am sticking with the step bumper/hitch.