Good to ask. Here are a few observations:
In my experience, it is really funny, when you go to build a kit, the first thought is always, "gotta go get a turbo" and then rush rush rush. That is what I did. Basically, all I knew was T-bird turbos work to make killer twin turbo 5.0 mustangs. Also I knew there are 3 flavors of Tbird turbos. Since my original idea was to build a cheap junkyard turbo setup, off I went to the local yard that had an 88 T-bird with a good turbo, pulled it and the manifold and paid 90 bucks. That turbo is an IHI which is one of the smallest tbird turbos. Now, I was locked in to find a second same one. Got that and off onto the build. The build itself and the other things associated with the setup now in retrospect were WAY more involved and in some cases more costly than obtaining the turbo. For example, originally I was going with a "free" fuel system: 140 lph intank pump, a spare procharger inline pump that was kicking around, an fmu that I bought for 45 bucks and stock 19# injectors. Ok not free, 45 bucks. Once I had my setup built, I was just floored by the amount of power you can get out of turbos, it is totally and utterly amazing. Now with all this power, I have this ify fuel system that has to run at 100 psi to supply fuel. With everything else working and driving so nice, I did not want to wreck my motor. So now, I go and buy the proper 42# injectors (230), PMAS maf (160), 255 lph pump (125) and all of a sudden I have 600 plus into a proper fuel system and 200 bucks into turbos! Of course, I wound up rebuilding the turbos myself so that was another 300 for parts and balancing. In retrospect, I probably should have waited and searched out the largest .63/.60 Tbird T3s but I think my setup is working really well with what I have. I can always build TT setup version 2.0..........
Anyway think ahead and plan. Think about your power goals. If you want, fast spooling hard hitting turbos but do not mind about 400 rwhp and 500 rwtq, the small bird turbos will work good. If you are dead set on 500 rwhp and up, you need the big uns. What is funny is the initial turbo cost will be the same or very similar!
97 Laser Red GT-248A Wingless model, Built Lincoln Mark VIII motor-Procharger D1SC, 3 core IC
2012 Black GT-Saddle, 3.73s, Brembos, Shaker1000