Any engine can be made to charge/boost and give an output several times the factory performance.
The real issue is tune and safety. Forged internals are really more for insurance and risk management as even the best tune is subject to variables that can end up being catastrophic.
A bad batch of fuel, an injector hiccup, the guy in the car not filling the tank all the way and launching with bad or factory sump at the fuel system leading to a lean condition....it's not usually power/torque on the dyno that nuke an engine, it's the guy going uphill in 4th gear on 100F day with a batch of bad fuel that results in pre detonation or too much spark timing for the conditions.
Having said all that, I think on E85 with a safe tune (and the fuel system upgraded accordingly to deliver enough juice) these engines should be fine at what they're currently being tuned out to....it's all a matter of how safe/robust the system is to account for unanticipated conditions.
I'd be more worried about the crank and torqueing on the snout for high hp (small pulley) setups than anything with the internals. That and I'd definitely want to ensure that the fuel system is upgraded (whether that means partially with a booster or even more with a new pump).
I'd also be worried that the drive train will be able to handle 800rwhp long term. Not so much about the trans/clutch but the IRS and half shafts. I plan on staying with street tires on mine so I'm not as concerned as the guys who are slapping on drag radials or full out drags and dumping the clutch with 550 ft-lbs at 3000 rpms, something has to give there and if it ain't the clutch, it's going to be the weak part of the hardware, which is probably the half shafts.