340

AND Don’t believe anyone that says there 318 went to a 340 bore unless you can see and measure it YOURSELF! Because it is more than likely a bunch of horse **** served to you on a silver platter.
Oh, I'm sure it has been done. Too many experiments have been done out there with this stuff to not have been done LOL. Seems like I read about it here some time ago...

Last time I shopped for 340 block, they were going for around $400-600 typically in the mid-Atlantic region. That was 2-3 years ago.

Easy to understand why to not to make 340 blocks. The real cost of starting production is 10's of thousands of $$$$$... both in time invested and tooling. Not anywhere near worth the risk for such a small market segment. It's not a wise place to invest one's time and $$, when you can take the same investment and make a lot more $$$ on a Chevy or Ford or even a SBM 360/5.9 part and with low risk. It's dumb TO do it. (FWIW, I've run my own business for 15 years....)