340 Block Bored to 4.160????? Help
Not trying to start any **** here but there is a "Maximum safe overbore" I don't make **** up. I read it years ago in a book by Larry Shepard. This is taken from a website found on a Google search of "Maximum safe overbore of Chrysler 340":
All 273-360 production blocks were cast using
a thinwall process and, as such, a .030" overbore should
be considered a maximum. Some older blocks (cast before 1976)
may tolerate up to a .060" overbore, however, whenever you
plan to machine the cylinders of an "LA" engine more
than .030" over size, it’s advisable to sonic check the cylinders
to ensure that core shift isn’t excessive. You may find, especially
with later blocks, that .020" is the maximum safe over bore.
The website is here:More Power From Your Mopar - Engine Builder Magazine
As someone who is a retired mechanic with some machine shop experience/knowlege, I just had to push this info out. Now, you can defy what the book says, but be wary of the consequences, its like cutting a brake rotor down to the thickness of a sawblade and wondering wny the caliper piston blows out. if you are running the engine 13 seconds at a time, it may last a few passes, if you want it to last in a street car, I'd follow the recommended specs.