Yea, dude you are right. For performance they can crack at the mount, however if you keep an eye on them, they normally will work. The way I do it is that everytime I have to crawl under the car I take a flash light with me (have to anyway) take a quick look at the fan anyway. I kind of run the drags 3 or 4 times during the summer and then hotdog it home. Do I beat on the engine a little, yep I do now. With a 401 in it, it can take some of the abuse (higher revs then what I use to do to the 360) and so far haven't had any serious problems with the fan. Can you provide some additional information of the zirt and where it actually goes. I remember them on some of the Chrysler products that my Dad use to drive. (63 Plymouth, 68 &69 Dodges etc).