500HP on a turbo 360 build will last for a VERY long time...

On one condition...

NO DETONATION!

There are 100's if not 1,000's of 500hp 360 N/A around the country that have been built.

Doing it with boost is generally easier on parts then doing in N/A. But if you get into detonation, that's when the cast crank will show it's teeth.

In general the cast cranks are more brittle then forged cranks. The forged cranks can take more shock (detonation) then the cast stuff can.

Be safe with timing, run good fuel, and watch the boost.

My Dad's Volare weighed 3890lbs this week. 340" with mild ported '308 casting heads, and a .550" solid cam went low 11's this weekend at the CC with 12lbs of boost... That's a very easy 500hp (probably more like 550hp+)

Good luck!