getting a high flow cat.... Looking to get a 2.5 round or oval core?

i just want to confirm which one to get for a 93 si.
from the looks of things the stock one on my car is a round?
just want to confirm this?

thanks HT

 

I think the only difference between the two is ground clearance. An oval would most likely fit more "snug" under the car.

 

I went with the round. Suits me just fine.