I was looking around for a high flow cat for my car and I really want to get a Magnaflow cat. When I went to their site, there were tons to choose from!! Which rating would be good enough for my car and flow well enough? There is the one that is rated for 5.9L engines and one for 7.8L engines. Would the 5.9L be big enough for my car? There is quite a bit of price difference between the two and I really don't want a cat that is going to be a restriction with all the money I spent on an exhaust system.

 

your motor is 5.7 so anycat in that catagory should be fine. Try the 9055. Just look up your application and see which one fits you best. They range from 2" to 3" cats. SO you shouldnt have a problem picking one out

 

I guess to further clearify my question: Since the cat rated 5.9 is basically right above the size of my motor, would it pose that much more of a restriction than the cat rated for a bigger motor?

Another question: Do the shorter cats have a higher flow than the standard legnth cats? They have ones that the main part of the cat is 12 inches long compaired to 9 inches long. I am assuming they probably have the same amount of catalyst so they probably flow the same?

 

I am going with magnaflow cats myself. However, the only reason some vary in length is for certain application restrictions such as crossmember etc. Smaller cats are usually best for being placed in a y pipe. If you are worried about the motor size try a catco or a dynomax cat or even a random tech cat.