Last month we finally got down to business with our 383 small-block build for project Lethal Weapon. AntiVenom put together a killer short-block for our ’87 Formula using a Lunati rotating assembly to take the 4-bolt main block to the next level, and then slid in a healthy Comp Cams roller. Though we’ve managed to assemble most of our parts to complete the long-block, there are always one or two essential pieces that will leave you hanging. Right about now would be the perfect time to go ahead and paint the block. Obviously, a whole tech article on priming and painting an engine block would be a real page-turner. Thankfully, a high-flow throttle body from Holley Performance Products arrived ahead of schedule, and a more interesting topic grew from our desire to make more progress on our fine-Firebird.
Increasing engine breathing is essential for getting better performance, no breakthrough information here. With that being said, going bigger with our ‘Bird means we want more airflow than stock. A 58mm High-Flow EFI Throttle Body from Holley (PN 112-503) is engineered specifically for 1985 to 1988 5.7-liter Tuned Port Injection Camaro and Firebird applications. The fully CNC machined unit is formed from 6061 billet aluminum, and uses the stock idle air controller and throttle position sensor, making for a simplified install. However, upgraded airflow means bigger bores—2x58-millimeters, to be exact. Since we elected to stick with a factory style TPI intake, we were going to be reusing the stock upper plenum, which meant we were going to have to bore out the openings to make sure the throttle body was being put to good use. With the upper manifold in our hands, we grabbed some paint and headed over to AntiVenom for the next phase of the build.