170 cc intake runner. They are still good enough to be EXTREMELY competitive in IMCA Stock car oval track racing. Watch this video at 2:50 seconds in. Devin Smith ran Mopar before the neutering rules and his sponsors made him change to Chevy and watch how he walks away every time even after restarts. He is who I bought my set of EQ heads from and the last Mopar he ran was a Chinese EQ-headed Magnum 360 and he dominated, he even winds it to 7,500 rpm and bounces off the chip. CC size isn't the only role in a performance engine. Get a camshaft tailored properly and you have port velocity-based performance.