just installed new aftermarket cooler Asus Silent Knight Cooler
 
temps after startup low 40's Deg C
 
temps at idle after warmup high 40's to low 50's Deg C
 
temps under load mid to high 60's Deg C
 
have already reseated cooler 3 times
 
not o'clocking
 
gigabyte 3d aurora case
 
 
Are these normal temps?

Yeah, there a tad high, but nothing to be worried about, what are you using for thermal paste?

asus TP that came with cooler

What are you using to monitor your temps?  I've got an e6600 also OC'd to 3 g's w/stock HSF and i'm getting 38-41 at idle and 50-53 full load.

You're getting those temps using Core Temp or TAT?  ...if so, not bad...not bad at all.

using core temp

One thing to think about is case ventilation and ambient temperature.   Your temps seem a bit higher that what I've heard others have.  However, if you have a case with a side windows (that may not, therefore, have a side vent) there's going to be less airflow and that can impact your temps...especially if you have a mid-to-high-end graphics solution.
 
To test this out, remove your side panel and after about 5 minutes measure your temps again.  If there's a big difference...
 
I ran into a somewhat similar scenario with my Thermaltake Mozart TX.   Great looking case but the airflow is not as good as my CoolerMaster C5.  I ended up getting a Tuniq Tower 120/AS5 which brings the temps back into orbit...62-63C with a 3Ghz OC under 100% load as measured by TAT after 10 minutes with the fan controller turned down to a QUIET setting (1400
RPM).  ...not a bad air cooler considering my case's airflow is not great.
 
Again, try running with your case open to see if there's a huge drop in temps, if so, perhaps you can put another intake fan in.