Re: Thanks for the help!

["Allan Ericson" <lowvolt@xxxxxxxxxxxx>]

Rocky-

When dealing with SV engines, (26 thru 392) there are two basic versions and
some minor variations with all of them. There are different piston types,
and the heads are different due to the combustion chamber differences.

In addition, the 392 internal cooling system was changed in about late 71 or
early 72 to route the coolant from the water pump through the block first,
then up through the heads, rather than the way the 266 thru 345 were done,
through the heads first. This was not done just in mediums, but rather was a
blanket change to the 392 design. All 392 engines, regardless of
application, are the same internally if manufactured at the same time.

A travelall 392 will bolt in and work in a loadstar.  The oil pans on the
different in order to clear the axles, the distributors are often governed
in the larger trucks, and the fuel delivery system was sometimes different
simply due to tuning. The oil pump pickups are different for different oil
pans so that the pickup tube will be at the bottom of the pan, as the
mediums have much larger oil pans. The engine mounts are different, but all
can be removed and swapped. In 1974, a change was made that allowed
mid-engine motor mounts to be used in pickups and travelalls, and this was
incorporated into the process as well.

The 304 and 345 had lighter duty versions made for scouts, pickups, and
travelalls. Don't be fooled by this. These "A" engines were far more rugged
than anything else you could find in a pickup truck by the time the smog
laws started to kick in.

The 5 speeds in the light line were used in the light mediums as well. These
are not light duty transmissions. IH used medium duty truck parts in their
light line vehicles, and the engines/5 speed transmissions are examples of
this. That 5 speed in a 3/4 ton truck will take anything that the truck's
suspension can handle. The biggest problem you are likely to encounter is
the huge gear change between third and fourth gear, from about 2.1 to 1 up
to 1 to 1, and that's only when towing, because you can wind up to 4000
rpms, shift, and then be below 2000 when trying to climb even a mild hill.
The flip side of that is that these engines brake very well. I've towed a
very large travel trailer with a 304, and kept the speed in check very
easily down a 7% grade.


----- Original Message ----- 
From: "ROCKY LEAR" <rockylear@domain.elided>
To: <ihc-digest@domain.elided>
Sent: Tuesday, June 10, 2003 10:01 PM
Subject: Thanks for the help!


> Thanks for all the input on the MV interchange info all those who
participated!
>
> After thinking about all of this....I think for the time being I will go
the 392 route. Is there an online info about performance mods to the 392
like overbore tolerances and such? How does the 392 differ from the 345
internally? Are 345 and 392 heads the same?
>
>
> I was talking to a guy here locally who ran IH pulling trucks a few years
ago. He claims that there was more than one version of the 392. He says that
there was a 392 made for heavy tandem trucks that had improved cooling. Can
this be confirmed? I have always ID'd the 392 by the coolant tubes running
back into the block instead of the head like a 345 does. Perhaps there were
some early 392's that had the tubes going back to the head and later years
had them going into the block...hence his comment about improved cooling.
>
> If I do go with the 392, will the 4 spd. with OD (OD 5th) that I have be
heavy built enough for the 4x4 3/4 ton truck? Could heavier pickups and one
tons be had with the OD back then?
>
> Rocky