The reliability comes from the bottom end being so strong as std, but for n/a the CR will need raising a lot, so new pistons as a minimum, not the best engine in the world for n/a imo, in ford terms I'd go duratec but depends on budget as well, the cossie crank is bullet proof for any n/a power level as are the rods.
I'd also look at vaux xe engines a lot better bhp/£ on n/a than converting a yb.
tabetha