Are you intending to use both the .45LC cylinder and the .45ACP cylinder interchangeably? If so, you should check to see if the new cylinder is indexing properly, i.e., the chambers are lining up with the bore. To do this you need a "reach rod", which is the diameter of the BORE of the cylinder and it should slide easily into each chamber. If not, the star may need to be worked on, and that IMHO is a job for the gunsmith. The problem is that, unlike fitting a single cylinder to the gun, you can't just work on the hand surfaces. You may need to work on the star contact points of both to get it right. Once in a while you will find you don't need any work on the indexing. I once bought a new .44-40 cylinder for an original Colt's Frontier Six Shooter because the original throats in the original cylinder were way undersized, and I didn't want to ream them. Bought the new cylinder and just for laughs tried it without doing anything to it. Locked up like a bank vault! And as I had specified .427" throats, it shoots like almost no other Colt's I've ever seen!
Best of luck with your project!