answers to the above questions below.
Well Im guessing the aftermarket lca you bought is adjustable? Yes it is, Length and RC.
so you can make it shorter or longer but remember since there adj is done from the bush end you effectively are pushing the sway bar and castor rod mounts out so you should try and install it and get it at the same length as the original arm and see if it fits if it still doesnt fit you make have the wrong lca. On R33's GTSt's the sway bar mount is on the upright not the LCA, but there is a bracket fouling on the sway bar which looks like it could be for the sway bar link on other models?
Below are some pictures explaining what i am talking about, If any one has used these or has some helpful information please let me know.