340 vs 360

turning a 360 crank and putting it into a 340 will give you the ability to use a substantially larger bore than you could with a 360. I have seen build with a 4.080 bore 340, but a 4.040 is about the most you want to push a 360 for street strip duty. The difference is about 12-14 cubic inches, my friend. There is no replacement for displacement, that's what my psychologist told me...LOL The reason you use 360 pistons off the shelf is the difference in compression height, or how close the pin is to the face of the piston. Off the shelf pistons are cheaper than stroker pistons. Right? 360 stroke, 3.58, 360 piston like KB's at an .060-.080 overbore, and you got a 372+ for less $$!!But you can't get a 360 block that will safely take an overbore of .080. Make sense? Thus, 340 block, $400, craigslist. Over all, still cheaper than a 408. Just my humble opinion, 340mopar, but it bears investigation. An extra 200 bucks for 12 more cubic inches? I think that's a good deal, myself.

He was talking about using off the shelf .060 360 pistons so the displacement would be the same. Sure the 360 would be .060 over and the 340 would be .020 over but that is of no issue other than it may be very difficult to find a 340 block that is a standard bore so it would clean up at .020. As for boring a 360 .060 over, it is of no issue. My 340 is .060 over and is just fine. I sonic check all of my blocks and haven't found one yet that couldn't go .060.

One other thing that hasn't been brought up is the 360 crank will be stronger with the 360 size mains than it will with 340 size mains.


Chuck