That quote is worthless. It's from the same source of the "thinwall 400s/440s" myth that was in every Mopar publication for years and years. The first I heard of this was in the very early '70s and back then it was considered gospel that the 496 block was the only 360 with the 340 core walls. As years went by it changed by, I think, wishful thinking.

RE: this quote, "all had thick walls ( around .200")".
Sorry, Charlie, the only place 0.200 is considered thick is in Moparland and some Ford circles.

Actually 0.200" is what's considered minimum for a major thrust in the rest of the old stuff. For Mopar engines if you can get 0.170" on a major thrust it's going to work. And the non-thrust parts of the block can go all the way to 0.120" and some won't even make that, and I mean virgin blocks! If you have 0.170" or more on all thrusts you go out and buy lottery tickets!

As for the thousands of 600hp 360s out there, I think they're all out racing those fabled 383 Hemis that Gramps had in his Road Runner. Put another way I don't believe it. If there are 100 360s making 600hp I'd be surprised.

If you had a 4.00" bore and 0.300" thick cylinder walls it'd be a Siamese block and you could go 0.200" over. It's being done with aftermarket smallblock chevy blocks right now. The largest area of concern is the head gasket between the cylinders.

R.