When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
If you're reffering to a Racing approved switch, i believe these must be located in the rear of the vehicle and are best used with a rear-mounted battery. check summit racing
There are a lot of options regarding a kill switch. You can install a solenoid/relay between the ignition and the starter solenoid... or in line with the fuel pump, or the power wire to the distributor...
My Suburban has a lead that opens/closes the lead to the distributor. If you don't enter a code, it dies. If you open the door at anytime and don't re-enter the code ( think: car-jacking ) it kills the truck after a 30 second delay. (Allows the guy to steal it, you to get to safety, and then recover it.)
Not sure on an '85 but isn't there a limit switch under the clutch pedal on the C5's? My thought would be to put an on-off toggle switch there so that the car would think the clutch had not been depressed and therefore not start...
I used to just do a relay with a lock and key that disabled the fuel pump .. started and ran for about 2 seconds before being useless. pretty simple to wire in, but these were older cars heh.