The weakest point on SVs is the crank, especially if you don't lighten the flywheel (which is part of the charging system as well). Rods on 2nd gens aren't too strong either.
You can get billet cranks, but even they break on a strong enough engine. The issue is that there's an oil hole that acts as a stress riser, so with each power pulse the crank twists a little, and eventually can crack and the flywheel end breaks off. You can also lighten the stock flywheel - in some cases retaining full charging ability, in some cases retaining minimal charging ability, enough for track but not street, in some cases getting rid of charging system entirely. You can also buy an aftermarket flywheel/stator assembly, brand slips my mind right now, that drops a lot of mass and gives charging system that's marginal for street but fine for track.
Anyway, the basic story is that it takes big bucks to build a reliable high power SV engine, but you can get a reasonable increase without spending a ton of money.