Re: 304/345/392 choices choices choices...

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

Jim:

I'm terribly surprised to see that you haven't been bombarded with opinions
on these. So, I'll share mine.

First off, it's the same motor pretty much across the board. The 345/392
has a slightly higher deck height to accomodate the longer stroke. These
"baby IH V-8s" for the light line trucks have an under-square bore that
produces more torque for a given CI than say a run of the mill Ford or
Chevy of comparable CI. These motors are also all truck. Very heavy, about
1,000 lbs wet (compare that to an SB Chevy at about 700 lbs wet or even a
BB Chevy at about 800 lbs wet) and very heavy duty. Gear driven cam vs
chain driven.

These motors are high torque, but not big on power. They  max out early in
the RPM range - 3800 RPM or so. They have brute strength for hauling, but
you won't win any drag contests. You can modify them with cams and various
intakes and such and even get them to rev to 5,000 RPM. But, after you
lived with one you might ask yourself why.


My Terra has a 304. I've found it to be plenty for all I do. I'd use a 304
just for the very slightly better mileage it will deliver over it's life,
if I just wanted to power my Scout. 

If you are going to haul a trailer, or fill the bed of a Terra with heavy
loads on a regular basis, then you want the 392. Make sure you find out
about the improved cooling and non-improved cooling versions before you
start, so that you can avoid interchange surprises later if you choose to
go that way.

The 345 is probably more common and easier to find than the 392. So, for
shear ease and availabilty and slightly more power than the 304, you might
want to go that way. The 345 had the most permutations - 2 BBL, 4 BBL
manifolds of different heights. Etc.

YMMV

Tom H.