So my 6.0 is stock exept the 918 spring and I know it will kick the bucket someday, so what does everyone think is important for a long life boosted engine making over 500 rwhp?

 

IMO you want to go upgrade the strength to forged / hardened.

If you are going there, you might as well have the block checked / cleaned up while its out.

Since you already have the block in the machine shop, you might as well punch it out

I'd do a nice forged 408 -- you probably want to step up the turbo at the point. You'll be able to spec exactly what you want in terms of CR and target your boost / power level. 8.6:1 is great for high boost, but 9:1 will work, and 9.5:1 if you're gonna keep the boost at 12 or so.

I'd go for diamond pistons again and a callies racemaster crank, but that's just my preference. Plenty of folks make good FI pistons. I wouldn't skimp on the crank or rods, budget permitting. I'd also step up all the fasteners to ARP high grade. I've got part numbers and specs up here