out side will work the best .i think if you did aY to oval 4 1/2 inch then back to a y mufflers out. it would work good i wanted to do a big oval ex for the gto but the car just is not that low. it sure would be cool . but it is $$ there is somethings i will spend money on if i can see it .i tell you on the chevy the car sit low in the front .i never cut the k trans crossover out was to strong to take out .so the ex kick down to the headers and kick back up over the cross member was not a big deal with small ex like 2 1/2 but with the 4 it down. it just cheap steel tubing. the roads are so bad that i use it as a skid plate ever now and then better then my oil pan