Imo circa 380 is good for fast road.

I suspect 500 HP is expensive, as you must need a 200 block to start with (probably long studded) and that's before you sort the chassis, brakes and transmission.

Technology has moved on though with twin scroll, roller bearing turbos and modern management etc, so imagine they would be easier to live with now.

Most seem to like Borg Warner turbo's from what I have seen.

I would question reliability though, given the reality it's 250 HP per litre, assuming the displacement remains the same.

Martin