Re: 392 block was 345 block

["Tom Harais" <tjhemh@domain.elided>]

Guys:

One of the guys I work with went to gunsmithing school in Colorado and
worked as an automotive machinest after he graduated. Of course, like most
fools he beleived he'd be better off with a "shirt and tie" job so now he
is a "traffic analyst" in our transportation department.

He tells me the "to the nearest ten thousandth" is for gun barrels. "To the
nearest thousandth" is for cylinder bores. He also says honing is too fine
a work to do what John L. said. It just doesn't remove enough metal to
allow for it's application. He says there is little to gain in going to
such fine tolerances in automotive work.

I had heard that some SB Chevy core castings were off-center (a bore) by as
much as 1/4" from the factory. He said he had seen them this way and worked
with them. Said you'd never notice short of some finicky, very finaly
balanced race motor turning 10,000 RPM or more.

Of course, he also told me the most accurate gun barrels in the world WERE
NOT CAST AND THEN BORED. Nope, he says they were hammer forged around a
hardened center rod. Go figure. Hammer forging steel produces a more
accurate barrel than solid stock with modern, close tolerance, machine
boring.

Tom H.