937DYTBOI
5,000+ posts
TL>you
how'd you do that, i use the biggest drill bit i have in my set, just over 3/4 i think. then used a rotary grinder to grind it out, but i did it low in the firewall to have the wire and fusebox as hidden as possible under the hood. got the grommet at lowes, i think it was 5/8th inside diameter, but it was pretty thick, OD was somewhere over an inch.
i found the exact size reamer that i needed for my grommet and the reamer punched straight through the firwall withe not much effort on my part, when u got the right tools installation is a breeze not to say i have all the right tools but that incident made me a believer
