the ticking sound is beause you mount the solenoid directly to metal. If you try mounting the aftermarket solenoid like the stock solenoid (put rubber in between) it should go away. I've couple of fren have the same prob. Dont quote me if I'm not right. Cheers.
Recently i've read up some articles, found out a good IC SHOULD not only lower down the temp but also to improve flow which shld be the factor if we ever wanna change it.