If you put 45psi on a stock 4.6 you need to bring a front end loader. A broom and dust pan will take forever to clean up the pieces of the engine. This is no joke, if you put a grenade into it you will get less damage. Your friend is full of sh*t. It doesn't really matter where the boost comes from, supercharger, turbo, hairdryer, leaf blower, etc. What matters is the volume of air you are trying to put in and the temperature of that air. At 45 psi, even if the air was -150 degrees the engine would let go like a bomb. The most I've seen on a 4.6 in person was 38lbs, and that was easily a 200k racecar. On a stock engine 8psi is the most anyone will tell you, maybe 10 if you have an excellent intercooler and tune, and don't mind risking blowing the engine.
The artist formerly known as SteedaMatt.