I've cracked one from nitrous at around 1400hp(started leaking water into the cylinder)...Indy said they have a thin sleeve & thick sleeve version(?)and I went back with the thick sleeve one as evidently I had the other...Really not sure about the block difference but info came direct from Indy !!
That is the later block, mine dose not have the webbing in the lifter valley. I'm shocked it broke at 1400, I had water in the oil issues before, now I run no water. I'll check it out better
