A Cat Guy

[the missing link]

Don't take my word for much , I have never owed a 550 but worked right beside lots and lots for them . My experience around them is this , a single turbo or a twin kicked back to a single is a typical die hard tough cat , a twin is if your lucky ,it keeps to head on her or gasket.
A good friend of mine has both. He does all offroad work , he says the twin does have a lot better hold of the load , but all the cats I have ever seen with issues were the twins.
My thoughts are ( keeping in mind I don't know my ass from a hole in the ground ) they produce way to much boost and that's what takes the heads out of them , I know Lots of guys take the same motor , kick it back to a single and they have a good strong motor.


Keeping in mind this is all offroad work , in the mud either logging or oil patch . We or they take trucks where most jacked up 4x4 pickups would laugh at you and think your nuts for thinking they would go there. These is not hi way work where fuel mileage , ect is a huge factor . It's all about getting in and out with as little abuse as possible on the trucks ,day in ,day out
Just my two scents