Sorry newb question, Magnaflow list only one.

I pretty sure they are but i could be wrong

no' the 5.7 has a larger pipe, if you're talking about stock.

Yup 5.7 flanges are bigger, So I decided to make it work. Cut out second cats behind rear O2 sensor, tigged on some stainless bends and made the 5.7 cat back work. Sounds great and fits the look of the truck now. Lucky I had some old subaru exhaust flanges that came off the race car that mated up perfectly, with the donut gasket. Know my two cars are bonded for life. Gained 18whp on a mustang dyno 20ftlbs torque, with catback and drop in panel filter. Not bad for a $600 investment. This is on a 4.7liter.
Matt
I will post dyno sheet when I get a chance.

Yup 5.7 flanges are bigger, So I decided to make it work. Cut out second cats behind rear O2 sensor, tigged on some stainless bends and made the 5.7 cat back work. Sounds great and fits the look of the truck now. Lucky I had some old subaru exhaust flanges that came off the race car that mated up perfectly, with the donut gasket. Know my two cars are bonded for life. Gained 18whp on a mustang dyno 20ftlbs torque, with catback and drop in panel filter. Not bad for a $600 investment. This is on a 4.7liter.
Matt
I will post dyno sheet when I get a chance.
I thought about doing something similar. I wanted a stock 5.7 exhaust on my 06, complete with the huge stock 5.7 muffler. It should flow well enough for a 4.7 but still remain quiet.

Just so I am clear on it, did you use the stock 5.7 muffler or the Magnaflow cat back which was meant for the 5.7?

I thought about doing something similar. I wanted a stock 5.7 exhaust on my 06, complete with the huge stock 5.7 muffler. It should flow well enough for a 4.7 but still remain quiet.

Just so I am clear on it, did you use the stock 5.7 muffler or the Magnaflow cat back which was meant for the 5.7?
Magnaflow catback meant for 5.7, Sounds Burly