Re: 392 block was 345 block

[Doug Rasmussen <DougRasmussen@domain.elided>]

John L wrote:
>I just got through cleaning and mic'ing all of the cylinders on this
wrecking
yard 392, and I've decided to go ahead and bore .030" over.  This means new
pistons.  So there's no way I'm going to clean 8 pistons of 27 years of
accumulated oil cokeing and rust just to figure this puzzle out.  I don't
need
to reuse the pistons so there's no reason to clean them.

I'll have to leave this search up to others with more time on their hands.<

John,

  I'll be curious to hear how your bore job comes out.  If your theory,
which seems
reasonable, about IH marking bores A, B, C according to bore tolerance is
correct that implies the factory had trouble holding exact tolerance on
bores.
If the factory had trouble, what does that say about a local machine shop's
ability to hold size?  

  On the engines I rebuilt I didn't check the bore size (for lack of
inspection
equipment at the time).  I just assumed the bores would be correct.  Now
I'm wondering.
Likewise, I didn't check size on the new pistons either.  Of course, it's
much easier to
maintain size on the piston OD than the cylinder bore.  At one time,
pistons were
available "unfinished".  That is, the final sizing of the piston OD was
left up to the
 rebuilder, presumably to match piston to bore.   Do auto machine shops
still do that?

Doug