I've heard that most of the time a 2 bolt or 4 bolt block will be fine with quality fasteners, unless you're building something with a stupid amount of power. thats when the splayed caps come into play because the outer bolts tie into a part of the block that has a lot more metal than the main webbing. but if you're making enough power to need splayed main caps, you'd probably be better off going with an aftermarket block all together.
gen III blocks (LS1 and such) are six bolt blocks. regular 4 bolts in from the bottom and two bolts in from the sides. badass straight from the factory!
