jbrew,
Do you have the 14" or 18" Magnaflow?
Was your 50 Series FM louder/quieter? More/less drone? compared to your current Magnaflow?

 

My Magnaflow is 24".. The magnaflow was quieter when I first istalled it , but it's hard to explain -it's more of quality sound. The 50 sounded like my stock unit with a hole in it. That's the best I can explain it.

Since then I've done more to the exhaust. I purchased reduced front cat's , I was suppose to get 2 1/4 but I got 2 1/8 (stock was 2 1/2) and I got rid of the rear cats all together.

Sounds just like a GT at start up and when driven normally and I have a SISO . Has a little popping when reved up . I always get asked if I have a mustang motor inner. The configuration turned out real well - I read about reducing the cats (reducing one and offing the other) in a troyer tune artical - keeping back pressure up and increasing overall torque , this also helped on the high end as well. O - 60 allot quicker than it was with all 4 cats.

I was beating stock 3 valve 150's before I did the cat upgrade , I haven't raced another since. I raced a old 5.0 Stang LX, u know , those go carts with a motor... That little sucker smoked me

If I was to do all over and new my cats where in good shape , I would just gut the front cats and leave rears alone - keep the whole system in one piece . I have 226,000 on my old cats and thought they may be bad so I just cut all the olds out..