Have you sonic checked 360 or even 318/340?

Rob R said

Bloody sonic tester...I have a BHJ and it ALWAYS brings the pain...
I think that a 340 block at .060 without a spot under .125 is doing pretty good..360's without a .090 or less spot somewhere is doing pretty good..
The days of 185 to 220 are long gone...IMO

Click to expand...

Agreed. That's why I sleeve now rather then keep testing and looking for better. I've got a couple 408s with pin axis thicknesses of .090 in service too.
I think a lot has to do with intent too. There's people that say they want a 550hp stroker that have no point of reference and will never use it and the sonic test forces them to take a closer look at their ambitions. 340s are not hard on walls. 360s really aren't bad either. It's the 1.5 rod/stroke ratios that start to push it as far as I'm concerned.