I'll be installing a Holley Pro-Jection 700-21 TBI system on a 5.7L GMC ( 1991 Mercruiser)long block. Holley's installation instructions state the system can be run in either the open (without O2 sensor) or closed (with 02 sensor). They also give instructions and photo's on how to drill and tap an exhaust manifold to install an oxygen sensor. Does anyone manufacture a manifold for this engine that comes pre-drilled and tapped for an O2 sensor?
Does anyone have any experience with this kit? Thanks for your help!
Does anyone have any experience with this kit? Thanks for your help!