[HardcoreZ28]

4L60's are tough from what I've been told. There are certain critical high stress parts that they don't make a stronger aftermarket version of so either way it's tough to build them up to handle lots of power. I have no personal experience pulling one apart but that's what I was told my 2 different trans builders when I blew the 4L60 in my pickup. That being said you may want to just look into a stock GM replacement with a warranty or have yours rebuild with upgraded clutches and so forth but know that there are still weak points that can't be addressed at this time.