I've run both UCF and Savvy skids. If you're not in a hurry wait for the Savvy skid to come back in stock. The two big reasons for doing so are:
- A separate cross member, allowing you to drop the skid and still have the transmission and transfer case supported
- More overall clearance, which can be seen in the pictures below
A not so subtle point that many miss is the ramping up on the sides of the Savvy skid. Unlike the UCF skid, where it's basically flat frame rail to frame rail, the Savvy skid has a small center section that's flat. It then angles up to flatten out at the frame rails.
The first two pictures are my current Savvy skid set up. Be warned that it does takes some work to get the exhaust tucked up and not rattling, but it's not a hard job. It just takes some patience and willingness cut exhaust mounts (on the pipe) and move them.
The third picture shows the UCF skid on my previous LJ. It's not as elegant as the Savvy skid but does the job, minus the two items I pointed out. Bottom line, if you're in a hurry, you'll likely need to go UCF. The one thing I do like about the UCF skid is the ability to add a 3/8" aluminum option. I wouldn't say it's mandatory, but if I were buying a UCF skid, I'd go that route. Whatever skid you do get, make sure you go aluminum. It's a decision you won't regret!
The fourth picture is a UCF stock photo, which shows the overall flatness of the skid.