[douhavit]

i have just purchased a sbc for street/strip and it has a holley dominator, single plenum. after pulling the carb for rejetting, i noticed about a 5/16" hole drilled in the center of the plenum which is allowing gas to be "stored". what should i do for this hole before reinstalling the carb ?...the engine was used on a drag strip, is this an old trick to help bogging and will it hurt intown driveability or be a safety issue...thanks in advance

[willys36@aol.com]

Sounds like an exhaust gas recirculation orifice. This is to reduce peak cylinder temperatures and thus reduce NOx so if the manifold is on pollution control exempt car or is strictly for drag racing, plug the hole by tapping it and installing an Allen hex set screw w/ red Locktite.