The World blocks are good, but have had a few issues. Who supplied the block for the build, you or Stanton? That would determine the warranty issue for me.

I have a World Hemi block and have dealt with the rear main seal leak, the right side water jacket machining issue and now I am dealing with a right side overheat problem. I hope I have a handle on this final issue. We'll see.

Ray Barton probably knows as much about these blocks as anyone. If he would take the time, he would likely be able to tell you what (if anything) you can do to address your problem.

I bought my stroker kit and cam kit from him. So he is my go-to guy on this engine. Frankly, it has been a pain in the a$$. Issues (like the one the OP has) and many others that just shouldn't have come up. So this is probably my last build. I am just sick and tired of doing everything 2 or 3 times due to issues that shouldn't come up. Rant off!