I tried to install my unorthodox crankshaft pulley yesterday night but i ran into some little troubles i'd need help with..

Here's a pic of both pulleys (oem VS unor.)
http://i50.photobucket.com/alb...5.jpg

As you can see the OEM one has a 50mm. 6 side hole to use a special tool to keep it from turning when you tighten the bolt holding it..

The other one doesnt have anything.....I tried using my old accessories belts and a C clamp to keep it from turning while i was tightening. I had to torque it a 160ft/lb (i have a torquewrench)
The problem is that i was never able to reach the 160ft/lb before everything slipped (tried many many times lol) I know for sure that i reached over 100ft/lb. (BTW; i used a new bolt)

I told myself i wasnt going to use an impact gun, but as pissed as i was i said f*ck it. It's a mastercraft electric one. (wich was able to undo a 2yo-no antiseize-applied-before-reistalling-axle nut (wich made me break a 1/2" breaker bar used with ginormagantuan 6ft pole "helper"))

When i tried the gun, the bolt didnt EVEN move at all (neither the socket lol) so it was too tight for the gun..

Now i'm kinda worried about driving my car like that because we all know that if that bolts comes loose, nasty **** may happen. I was thinking about doing some light testdriving around my house then re-checking (with the impact) if everything is still tight.

What the f*ck can i do to make sure it wont mess up? This thing really worried me at this moment

Thanks!