i sold him this b16a with my DA9, it's a JDM EG6 b16a and they are either supertech or crower retainers (can't really remember), the head was shaved, and i've replaced the OEM headbolts about 1.5...
there should be 3 wires at the back of your each gauges, 12V ( should be in red, may be orange ? ), ground ( black ) and sensor ( depends on what gauges u have, i am guessing yours will be purple ? )...
i couldn't tell the different with most of the "mods" , some people tell the different even with a C pillar installed, i can't feel shit even with the roll cage.......the only different that i can...