You kind of answered the question already by the statement "an awful lot of
trucks using the 350/400 combo so it must be a good one".
Like the 2-bolt / 4-bolt question, the 2 bolt was more of for the non
working trucks that weren't going to need the extra low end protection due
to added stress from towing or carrying heavy loads. Most all work trucks
have the 4-bolt main engines for that reason.
The 400 transmission was also the heavier duty item between the two and that
is again why you saw it in work trucks or behind Hp engines.
I think I remember you saying the truck was mainly going to be used for
cruising and so as long as you pick a 700R4 built after 1987 you should be
just fine. Your going to love the lower first gear ratio for acceleration
and the overdrive for gas mileage. I plan to purchase my 700R4 transmission
from Bow Tie Overdrive http://www.700R4.com/ . They got back to me with the
following information:
The Th-700R4 have the converter lock up which is a marvelous feature for
eliminating the heat production inside the converter and increasing your
fuel economy while lowering you cruise rpm a couple hundred rpm while locked
up.
Let me give you some numbers to play with.
Th-700R4 (4L60) transmission with a heavy duty torque converter is $1020.00.
We use nothing but late model (1988 to 1993) cores. We then perform a
blueprint overhaul using only quality brand name components like Raybestos,
Alto, Borg Warner, Torrington, Delco Remy etc. Every transmission features a
new pump hardened steel pump rotor and vanes, hardened steel guide rings,
double and stronger (high rpm operation) slider springs, H.D. Sprag, output
Planetary with hardened ring gear and H.D. Pinion gears, New bushings
(doubled in most major areas), Custom made (to our specs) one piece teflon
seals, high temperature center seal, custom built servo assembly (our
design), larger boost valves (both the main and the low/reverse), special
accumulators (our design), custom shift calibration (our specification),
nine frictions and steels in the 3/4 clutch pack with a special backing
plate, special band anchoring just to name a few things. We perform over 40
upgrades and modifications for increased durability and strength. The torque
converter features a Kevlar friction, largest Lux dampening assembly
available, torrington bearing to replace the thrust washer, largest
available sprag, new steel pump drive bushing, brazed turbine vanes and the
assembly is precision balanced for smooth operation. These converters are
available in 1800 or 2200 stall speeds at the above price.
T.V. (throttle valve) cable adapter system for your carburetor is $42.00.
This cable controls all pressure manufacture and is the major outside
influence on shift timing and feel. The importance of getting this system
calibrated for your vehicle cannot be overstated. While other companies tell
you it's important, we offer the parts and easy to follow instructions on
how to establish this relationship correctly. All of our transmissions come
with illustrated instructions on this critical set up.
Zero to 300 PSI gauge with six foot hose and close 90 degree fitting is
$28.00. This is a basic diagnostic tool that we require be installed during
the start up and test driving to confirm the pressures are the same as when
the transmission left our test stand.
Speedometer calibration gear set is $44.00. This is all new Delco parts and
is everything except the speedometer cable and the gauge. We will need your
tire size and rear end ratio to accomplish this. When you get the
transmission installed, all you will need to do is screw the speedometer
cable onto the transmission drive gears and your speedometer should be
correct! If you are planning to run electronic gauges, there is no charge.
These transmissions already have electronic speed sensors built in that will
interface with the after market gauges.
Brake pedal switch that will disable the converter lock up whenever you
press on the brakes. This feature will prevent you from killing the engine
if you should skid the rear tires while braking. This switch will replace
the old one under the dash.
Plug in wiring harness for connecting from the transmission to the brake
light disconnect switch or relay.
-----Original Message-----
From: Rick Carlisle <rcarlisle@home.com>
To: oletrucks@autox.team.net <oletrucks@autox.team.net>
Date: Wednesday, July 18, 2001 5:13 AM
Subject: [oletrucks] TH400 vs. 700R4 transmission
>Thanks for the responses on 2 bolt vs. 4 bolt engines. Very helpful.
>
>I have another question. I was virtually "sold" on using a 700R4
transmission
>before the 350 engine/400 transmission deal was offered to me. I admit I
>really don't understand the significance of one vs. the other except the
700R4
>has an overdrive that could help on the highway. But I see an awful lot of
>trucks using the 350/400 combo so it must be a good one.
>
>Can someone help me understand the advantages/disadvantages to using the
TH400
>vs. the 700R4? Thanks.
>oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
oletrucks is devoted to Chevy and GM trucks built between 1941 and 1959
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