[SS Engine Guy]

What Bub said! And to add I have used cast cranks in S/SS cars of all kinds over the years. The most important part is to mag properly and to have someone with the experience to read what the mag is telling them. Good balance job and you are good to go. I usually run cast cranks 4 years as long as the magnaflux viewings haven't changed in 3000+lbs cars. If the balance isn't correct it dosen't matter if you have an unobtainium crank and 8 bolt mains it is coming apart. Just imagine at 7000 rpm the explosion that is going off in the bottom end when something breaks. Personally I have also seen more broken forged cranks than cast. Also just because the local machine shop has the latest greatest balancer dosen't mean that the guy operating it knows what he is doing. If you haven't ever seen or had this done, find a shop with all the BHJ block-true fixtures. The variances in a SBC will make you wonder how it ever went 10 miles in a passenger car much less a racecar. Find a company or crank grinder that can talk to you about fillet radius, crank snout runout, etc and you won't have a problem.