greddy exhaust and oem magnaflow cat issues

Ok so i just put up a greddy sp exhaust and it bolted up nice. but when it came to the cat i ordered a magnaflow oem replacement its to long and will not bolt right up. on top of that i also have a replica header with a 2.5 in diameter and it sits lower that the greddy exhaust. so the cat will not bolt up to the header being that the header flange is to big and the cat is to long was wondering if anyone had this type of problem and what was the fix for it. any input would be great. thanks in advance.

Bump

Return the cat and get a universal style one. Install the header and exhaust, fab the cat w/ the appropriate length and flanges. Use a 2.5" cat. You can see a pic of the one I made for my car in this thread: http://forums.g2ic.com/showthread.php?202303-header-and-exhaust-size&highlight=smsp

will the 2.5 cat make my car any louder

There shouldn’t be a significant difference in noise level between different sized cats as long as you’re comparing with the same brand/model just a different size. There may very well be differences if you compare between brands or an oem style vs high flow.

Well im thinking the high flow cats are going to be louder than the oem style. Plus when using a high flow cat you tend to get that fuel smell i cant stand that thats why i chose an oem style cat