Start with the alignment specs for the donor vehicle, and hope the person or shop that did the swap knew what they were doing. There are so many variables like ride height, spring rates, wheelbase, scrub radius, Ackerman angles, etc. that any alignment attempt is only going to be a WAG. Tinker with it a lot, and see what works for the best handling and tire wear results. Some of the aftermarket kit suspensions get things so out of whack trying to get the slammed look that there's no practical way to make the alignment work.
Jerry