View Full Version : What throttle body and mass airflow sensor sizes are recommended?

10-28-2002, 07:49 PM
By Bill Evanoff

Enlarging these two items will substantially improve the incoming air flow capability to the engine. The SCCoA recommends the 73mm C&L or 77mm Pro-M units. Remember that your MAFS must be calibrated properly to your injector flow capacity. The stock size on 89 to 91 SCs is a puny 55mm. The later models had a larger 70mm size but this sensor body has a large bridge going through it, which limits its flow to only a few CFM more than the 55mm. Boring of the 55mm or removing the bridge on the 70mm is not a recommended practice, as it will slightly alter the calibration of the stock sensor. Either stock sensor housings should be replaced on any serious SC engine wishing to make more power. The stock throttle body size is a rather restrictive 60mm. The recommended performance throttle body is a 70mm diameter aftermarket piece made by Edelbrock/BBK with the linkage specially modified to fit the SC. The SCCoA sells these throttle bodies already modified or if you can weld, your stock throttle body will have to donate its original linkage in order for you to complete the modification yourself. A 75mm size is available for higher HP engines but really is overkill on anything but a full race setup. Supposedly BBK is working on a 70mm SC throttle body that does not require any modifications, but as of this printing it is still not available.