Can anyone ID this trani? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

my new 72 · 04-20-2002, 02:51 PM

It is a turbo hydramatic, but that is all I know. The numbers are as follows:
80-03-23871
8632145 Lester-5
on the case is weld marked 93Cx
What is it, a turbo 350 or a turbo 400?

Longhorn Man · 04-20-2002, 02:56 PM

What does the pan look like?

------------------
'69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man
I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it.
FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite.
If you need a pic posted, E-mail me at longhornmail@yahoo.com
Andy, in Columbus Ohio

my new 72 · 04-20-2002, 03:32 PM

Good question. I will be right back.

my new 72 · 04-20-2002, 03:37 PM

It look like it would be a THM350. Does the 80-03 mean that it was made in March of 1980
It also has an electrical plug on the side of it. What would that be for on a th350.

Longhorn Man · 04-20-2002, 03:43 PM

The plug would be for a lock up torque converter, and with that said, '80 would be about right.
I know you can wire a toggle to it to activate the lock up, but I couldn't tell you how.

------------------
'69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man
I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it.
FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite.
If you need a pic posted, E-mail me at longhornmail@yahoo.com
Andy, in Columbus Ohio

my new 72 · 04-20-2002, 03:54 PM

I am still learning, so help me out a little. What is the function of a lockup torque converter. Does it act as an overdrive gear or what? Forgive the dumb question, but I know nothing about transmissions.

Longhorn Man · 04-20-2002, 04:08 PM

At all speeds, you will have a little slipping in your transmision.
If you put 2 window fans facing each other, and put one on high, the other turned off, the one that is off will spin, but at a lower RPM. That is how your verter works.
When it goes into lock up, picture an arm reaching out from one fan, to the other, mechanicly locking them to one. The fan driven from the engine will be locked directly to the fan driving your tranny.
The RPMs will drop, but only by a couple hundred RPM. (from say 3200 to 3000)
The way they are done up from the factory, they verter will only go into lock up under certian criteria;
1. steady engine speed
2. 45 (ish) or faster
3. foot off the brakes
4. in top gear. (3rd on your tranny)

------------------
'69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man
I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it.
FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite.
If you need a pic posted, E-mail me at longhornmail@yahoo.com
Andy, in Columbus Ohio

[This message has been edited by longhornmail (edited April 20, 2002).]

O'l Buck · 04-20-2002, 04:09 PM

the lockup in the coverter acts as a clutch, giving a direct link between the engine and the transmission inside the torque converter. This allows for quicker acceleration, and engine braking. It will also reduce the temp of the transmission at highway speed due to the fact that the converter is not agitating the fluid so much.

------------------
Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84
ralleys and 31/10.5s

Angel girl: 67 Cutlass convertible
330, 3spd stick

Greener: 90 GMC Jimmy
350/auto
Chad Stephens
Orleans,NE

no name yet: 72 442 under serious construction

my new 72 · 04-20-2002, 04:20 PM

Would it be worth rebuilding to go with my new engine? I am building a 383 .40 over, 274 crane energizer cam double roller timing chain and gears, 72cc Dart ProI aluminium heads, which equals 10.2 to 1 compression. The cam is rated for a band starting a 2200 rpm thru 5500 rpm. With an edelbrock intake and a fresh Rochester 4bbl I will be pushing close to 475hp. I would rather have od but the engine is costing me more than I am allowed to spend at this point in project.

O'l Buck · 04-20-2002, 04:23 PM

A th350 is a tough transmission, they take abuse well and peform nicely, on the other hand, the th400 is alot tougher, alomst bulletproff if not. But the 350 should do a nice job.

------------------
Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84
ralleys and 31/10.5s

Angel girl: 67 Cutlass convertible
330, 3spd stick

Greener: 90 GMC Jimmy
350/auto
Chad Stephens
Orleans,NE

no name yet: 72 442 under serious construction

my new 72 · 04-20-2002, 04:28 PM

Thanks for the info guys. I WANNA SEE THAT 442 Buck. 4bbl 4speed Dual(2)exhaust. A very cool car indeed.

Longhorn Man · 04-20-2002, 04:36 PM

The 350 will be perfect for your truck. When you go to get it rebuilt, ask about teh lock up, and get a pro's advice on if, and how you can do it. Also tell him exactly what you are pushing (a heavy truck with a butt load of power) and how you'll be using it. He will build it acordingly.
As for an Overdrive tranny, stay away from them. With the power you are making, the tranny will cost more than your motor. (maybe not more, but more than you wanna pay)
Build up your TH350 (which eats less power than a TH400) and later on down the road, you can add a gear vendors over/under drive. These things are bullit proof. http://www.gearvendors.com/commercial.html

------------------
'69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man
I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it.
FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite.
If you need a pic posted, E-mail me at longhornmail@yahoo.com
Andy, in Columbus Ohio

04-20-2002, 02:51 PM	#1
my new 72 faster, faster, faster Join Date: Dec 2001 Location: Houston ,Texas ,USA Posts: 1,354	Can anyone ID this trani? It is a turbo hydramatic, but that is all I know. The numbers are as follows: 80-03-23871 8632145 Lester-5 on the case is weld marked 93Cx What is it, a turbo 350 or a turbo 400? __________________ I'm going to Law School, wanna debate? It's good practice.

04-20-2002, 03:32 PM	#3
my new 72 faster, faster, faster Join Date: Dec 2001 Location: Houston ,Texas ,USA Posts: 1,354	Good question. I will be right back. __________________ I'm going to Law School, wanna debate? It's good practice.

04-20-2002, 03:37 PM	#4
my new 72 faster, faster, faster Join Date: Dec 2001 Location: Houston ,Texas ,USA Posts: 1,354	It look like it would be a THM350. Does the 80-03 mean that it was made in March of 1980 It also has an electrical plug on the side of it. What would that be for on a th350. __________________ I'm going to Law School, wanna debate? It's good practice.

04-20-2002, 03:54 PM	#6
my new 72 faster, faster, faster Join Date: Dec 2001 Location: Houston ,Texas ,USA Posts: 1,354	I am still learning, so help me out a little. What is the function of a lockup torque converter. Does it act as an overdrive gear or what? Forgive the dumb question, but I know nothing about transmissions. __________________ I'm going to Law School, wanna debate? It's good practice.

04-20-2002, 04:09 PM	#8
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	the lockup in the coverter acts as a clutch, giving a direct link between the engine and the transmission inside the torque converter. This allows for quicker acceleration, and engine braking. It will also reduce the temp of the transmission at highway speed due to the fact that the converter is not agitating the fluid so much. ------------------ Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84 ralleys and 31/10.5s Angel girl: 67 Cutlass convertible 330, 3spd stick Greener: 90 GMC Jimmy 350/auto Chad Stephens Orleans,NE no name yet: 72 442 under serious construction __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska

04-20-2002, 02:56 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	What does the pan look like? ------------------ '69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite. If you need a pic posted, E-mail me at longhornmail@yahoo.com Andy, in Columbus Ohio

04-20-2002, 03:43 PM	#5
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	The plug would be for a lock up torque converter, and with that said, '80 would be about right. I know you can wire a toggle to it to activate the lock up, but I couldn't tell you how. ------------------ '69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite. If you need a pic posted, E-mail me at longhornmail@yahoo.com Andy, in Columbus Ohio

04-20-2002, 04:08 PM	#7
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	At all speeds, you will have a little slipping in your transmision. If you put 2 window fans facing each other, and put one on high, the other turned off, the one that is off will spin, but at a lower RPM. That is how your verter works. When it goes into lock up, picture an arm reaching out from one fan, to the other, mechanicly locking them to one. The fan driven from the engine will be locked directly to the fan driving your tranny. The RPMs will drop, but only by a couple hundred RPM. (from say 3200 to 3000) The way they are done up from the factory, they verter will only go into lock up under certian criteria; 1. steady engine speed 2. 45 (ish) or faster 3. foot off the brakes 4. in top gear. (3rd on your tranny) ------------------ '69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite. If you need a pic posted, E-mail me at longhornmail@yahoo.com Andy, in Columbus Ohio [This message has been edited by longhornmail (edited April 20, 2002).]

04-20-2002, 04:20 PM	#9
my new 72 faster, faster, faster Join Date: Dec 2001 Location: Houston ,Texas ,USA Posts: 1,354	Would it be worth rebuilding to go with my new engine? I am building a 383 .40 over, 274 crane energizer cam double roller timing chain and gears, 72cc Dart ProI aluminium heads, which equals 10.2 to 1 compression. The cam is rated for a band starting a 2200 rpm thru 5500 rpm. With an edelbrock intake and a fresh Rochester 4bbl I will be pushing close to 475hp. I would rather have od but the engine is costing me more than I am allowed to spend at this point in project. __________________ I'm going to Law School, wanna debate? It's good practice.

04-20-2002, 04:23 PM	#10
O'l Buck Recovering Truck Driver Join Date: Mar 2002 Location: Orleans, NE USA Posts: 1,883	A th350 is a tough transmission, they take abuse well and peform nicely, on the other hand, the th400 is alot tougher, alomst bulletproff if not. But the 350 should do a nice job. ------------------ Ol' Buck: '72 Chevy 1/2T 4x4 shortbox stepside 350/350auto on '84 ralleys and 31/10.5s Angel girl: 67 Cutlass convertible 330, 3spd stick Greener: 90 GMC Jimmy 350/auto Chad Stephens Orleans,NE no name yet: 72 442 under serious construction __________________ 67 K-20 350, SM465, Eaton rear, 4.56 no spin option 00 Dodge 2500 4x4, 24V cummins, 5 speed Chad South Central Nebraska

04-20-2002, 04:28 PM	#11
my new 72 faster, faster, faster Join Date: Dec 2001 Location: Houston ,Texas ,USA Posts: 1,354	Thanks for the info guys. I WANNA SEE THAT 442 Buck. 4bbl 4speed Dual(2)exhaust. A very cool car indeed. __________________ I'm going to Law School, wanna debate? It's good practice.

04-20-2002, 04:36 PM	#12
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	The 350 will be perfect for your truck. When you go to get it rebuilt, ask about teh lock up, and get a pro's advice on if, and how you can do it. Also tell him exactly what you are pushing (a heavy truck with a butt load of power) and how you'll be using it. He will build it acordingly. As for an Overdrive tranny, stay away from them. With the power you are making, the tranny will cost more than your motor. (maybe not more, but more than you wanna pay) Build up your TH350 (which eats less power than a TH400) and later on down the road, you can add a gear vendors over/under drive. These things are bullit proof. http://www.gearvendors.com/commercial.html ------------------ '69 G.M.C. 350/350. Trying to clean up the left over damage from the Dope-Smokin-Old-Man I've been dubbed the Longhorn Freak/Fanatic/Expert, I just hope I can live up to it. FINALLY got the HORNIAC...a '70 one ton Longhorn with a Pontiac 350/350 and lots of 'personality'. Check out The Longhorn Webite. If you need a pic posted, E-mail me at longhornmail@yahoo.com Andy, in Columbus Ohio

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