Drilling into the firewall for gauge wires. best place for holes to prevent water in?

[85begalttype]

im half way through my frame off restoration. Going to drill some holes in the firewall for gauge wires and hotwire kits..etc. on the passenger and driver side of the firewall. In the future im going to get the AEM wideband o2 sensor, i was wondering how big of a hole i should drill into the passenger side to feed the sensor through. and where would be the best place? close to the ecm harness hole? best place so that water cant get inside... is the aem gauge connecter smaller than the o2 sensor? would 1inch hole be big enough or can i go smaller?

 

[BRAD_PADGETT]

Don"t drill any holes at all. Use the grommet under the steering wheel for your gauges. Run the wideband o2 wires under the center console next to the shifter cable then to the firewall under the console. Brad

 

[85begalttype]

Don"t drill any holes at all. Use the grommet under the steering wheel for your gauges. Run the wideband o2 wires under the center console next to the shifter cable then to the firewall under the console. Brad

im using a cutlass body and i forgot there was already a spot under the steering column that just needs to be pushed out. thanks and i was thinking of using the shifter hole but thought maybe the cable might wear into to the sensor wires overtime?

 

[BRAD_PADGETT]

im using a cutlass body and i forgot there was already a spot under the steering column that just needs to be pushed out. thanks and i was thinking of using the shifter hole but thought maybe the cable might wear into to the sensor wires overtime?

Four years later and there have been no issues with the wideband wires coming up from the center console. I installed the wideband on the test pipe and ran the wires directly over the to transmission cable up into the center console. The wideband sensor faces the center of the car. Brad

 

[85begalttype]

ok thanks for the quick response, i will do that. Cant wait to get this car back together