2.5inch twins into 2.95inch
VS.
2.75inch twins into 3.15inch (or 3.35inch)
Consider that they need to flow enough for 1.3ltrs each. Or to break it down further, only enough power for up to 150kw each. Easily doable with 2.5" crush bent exhaust, I made 170kw atw in my old 626 wagon with 2.5" crush bent system.
What size cat and exhaust are you running? 3"?