Originally Posted by danzcool

If 500 is your ultimate target and you plan to supercharge, the either will work fine. The aftermarket parts should be cheaper for the 4.6 but they are no longer casting the 4.6 blocks, so if eventually you want to go forged, you can easily get a brand new 5.0 block but the 4.6 will likely be a refurbished block.
All that said, I know when it comes to BIG power there is a weakness in the 5.0 design currently that hopefully will get worked out (the sportsman block is an attempt to resolve that weakness).
But at under 600 on the 5.0 you would be nowhere near the level to cause any issues with the current design.

Originally Posted by awbreyjd

I was at a mechanic when we did my heads/cams, they had a 2012 5.0 there and we noticed the block seemed to be cast slightly different when compared side by side. But I can say that my 5.0 with power in sig running to 7800rpms has lasted about 60 passes down the track at the current power level and is still running strong.