don't remember on the end links but it was a little tough to put the rubber bushings on the 'u' clamps that bolt it to the frame
this may sound stupid but are you mounting it the right way? Also you are sure it's the correct bar? I'd go out and check but it's dark out and got to be really cold now. (11pm)
Mine is the same way, they are at a slight angle, so far so good, I bought a proper length set of energy suspension sway bar end links from AutoZone and trimmed the center spacer for a correct fit to put the sway bar horizontal with the ground.
The reccomended sway bar is from the IROC-Z28 which was 1mm smaller than the Trans Am of the same era. The arms on either bar are about 1 inch shorter than the Impala Sway Bar. This makes the end links work at an angle. IF you search there is a thread somewhere showing how one member made brackets to move the mounting points back on the cross member which restored the stock alignment with the end links.