30 vs 35 spline axles

From what I have learned, the difference is significant but unless you're planning on building a super hot big block or abusing the heck out of the rear end, the 30 spline axles will almost certainly do the job and the money (assuming this is a consideration...and we're A-Body people so it's a safe guess :D ) would probably be best spent on other components of your build.

If guys have specific information on this, I'm all ears.