We all know, most premade harnesses fit poorly. All the Holley Harnesses I've used, needed to be de-loomed, things moved, removed, added and trimmed. That is what this kit is designed for. Both 58X and 24X 

It's as simple as, de-looming your harness, stick it on the engine, cut off the old connectors, add the new ones, use the cut off connectors as a template to pin the new connectors. loom it, and impress people with poor fitting wiring harnesses. 

below is a list of connectors included. each connector, should be hyperlinked to the individual connector, where you will find a video showing how to assemble and what crimpers to use. if it's not hyperlinked or link is broken, you can just paste the connector in the search, and it should take you to the page. 

it may look intimidating or complicated, but if I can do it...... 

(if you want to build your own kit, you can use the list below to easily get to most the connectors you need, our search is also very good) 

1x 10 Way Female Metripack 150 Receptacle Connector Kit (Fuel Injectors)

3x GM Pressure / Holley TPS Sensor Connector

2x GM, Holley Cam/Crank 24X Cam58x sensor connector (1x 24X Crank sensor, 1x Cam)

2x 58x Crank or MAP Sensor Connector (1x 58X Crank Sensor,1x MAP Sensor)

2x Male coil harness connector

1x GM CTS connector

1x GM IAT/MAT connector

1x Bosch O2 Sensor Connector (can be used to wire directly to, without an adapter)

1x Holley In out, Coil pack, O2, universal connector (O2 sensor) 

1x GM IAC Connector

1x extra pins & seals for most connectors