If I recall correctly it can handle a measly amount. Something like 5 PSI. However, I could be completely wrong. I am more familiar with the 4.6 platform.
Pistons are not forged from the factory. People have done it. Some have had luck going up to 8lbs with good tunes and others have lost it at as low as 5lbs. It's all a game of chance and knowing your tune This message courtesy of crapatalk!
^^ This guy had a turbo setup. Its all in giving it the fuel supply it needs, a tune thats spot on, not getting greedy with HP numbers and the 93-95 5.0L bottom ends can last.
I couldn't agree with you guys more! It was a turbo setup with a conservative tune. Car made 415rwhp/440rwtq on a mustang dyno. It could have easily made way more but I played safe.
Run the fel pro gaskets and yes you can run a lot of boost. I personally have detonated on high boost and only pushed gaskets. 400rwhp is a very safe number on these cars just have a wideband and monitor while you are driving
Best way to get power out of these blocks is less timing and more boost, rather than more timing and less boost