i have the 08 tundra 300 which has the single a arm front end. I believe the 550 that year has the same idea just a wider stance and beefed up a bit. they are built weak to say the least, infact thats why i own one! front end was a right off....iam a sucker for winter fixer upper projects.
ive heard alot of good things about the new redesigned front suspensions