how to tell a th350 from a th400 - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Chevy1972/GMC2000 · 02-11-2008, 09:18 AM

I was just woundering if someone could tell me how to tell a turbo350 from a turbo400 trans. My trucks trans is option coded as a M49, what trans is that?

**Palf70Step** · 02-11-2008, 09:39 AM

Looking at the shape of the pan is the easiet way.

cruiserman · 02-11-2008, 11:28 AM

400 oil pan is shaped like Texas.

Longhorn Man · 02-11-2008, 01:08 PM

quick and easy;
kick down cable = TH350
No kickdown cable = TH400

**68350** · 02-11-2008, 04:23 PM

nother quick way,
th400-6 bolts in the tail housing
th350-4 bolts

Machinist1972 · 02-11-2008, 04:30 PM

The top right transmission in the picture is a turbo 400 transmission. I look to see where the modulator valve is. It should be on the passenger side closer to the front when looking at the transmission from the back.

BLE 'BURBAN · 02-11-2008, 04:32 PM

TH350 vacuum modulator faces right
TH400 Vacuum modulator faces back

72armyswbtruck · 02-11-2008, 05:42 PM

Boy look at all those ways to tell the difference

blukangoo · 02-11-2008, 05:56 PM

Just like everyone else said:

TH350 has a Mechanical (cable) Detent Cable.
TH400 has an Electrical Detent Switch.

Easiest way is the shape of the drainpan.

**LostMy65** · 12-01-2010, 11:52 PM

Thanks for this thread. I now know I have a 350.

blukangoo · 12-06-2010, 01:53 PM

Cool to know that people still read threads that are 2 years old.

JointTech · 03-26-2012, 11:05 PM

no 4 years old. I just found out i have a th400 Thanks.

mmmm thread necro

dads longhorn · 09-17-2012, 02:57 PM

Thanks for the thread, now I know I have a 350 TH.
Is there a preference 350 vs 400? Thanks again

catch2otwo · 03-17-2013, 04:29 PM

Anyone have a good recommendation of a deeper sump aluminum pan with a drain plug like the one pictured above?

Tx Firefighter · 03-17-2013, 04:38 PM

Quote:

Originally Posted by catch2otwo

Anyone have a good recommendation of a deeper sump aluminum pan with a drain plug like the one pictured above?

I've had a few of these over the years. They don't exactly give them away, but if you like quality, you've found the best.

http://mag-hytec.com/store/index.php...products_id=97
Posted via Mobile Device

**Palf70Step** · 03-17-2013, 08:28 PM

Here is what I used on MY T350
http://www.jegs.com/i/Hughes+Perform...FQzNnAodpGwAaQ

mrsmith · 08-22-2016, 05:26 PM

I know this is a really old thread ,but it is still VERY useful to us that are not quite up to the level of some of you other guys . I figured out i have a TH350 thanks to this thread without breaking any kind of sweat. thank you everyone for sharing your knowledge.

factorystock · 08-22-2016, 10:26 PM

Quote:

Originally Posted by Chevy1972/GMC2000

trans is option coded as a M49, what trans is that?

Ok, OP is long gone, however GM did cause some confustion by listing the same SPID code M49 for both "turbo hydramatics" in some years.

GASoline71 · 08-22-2016, 11:02 PM

But the SPID was telling the truth...

Gary

Nachos82 · 02-04-2017, 04:55 PM

Right on fellas, and thanks blukangoo for the unmistakable picture of the two different pans.

Yea, this thread is old as crap, but it's the first Google search result that appears when you do "how to tell th350 from th400" and it was worth my efforts to log into the site and surf around like old times.

I got a camaro last month and was wondering if it had a th350 or th400. Figures the best truck forum out there had the answer to my question.

Upon deep investigation, if I had only waited 7 more days I could have made this a 9 year spread from initial post to my reply. Oh well, guess nobody can be that awesome.

towbar · 02-04-2017, 08:27 PM

another quick and easy......governor gear has a 4 bolt cover on a T400, a clip bail cover on a T350

hotwls13 · 06-20-2018, 04:55 PM

Quote:

Originally Posted by BLE 'BURBAN

TH350 vacuum modulator faces right
TH400 Vacuum modulator faces back

Old thread but just read this. I have a 350 (according to PAN) and the Vacuum modulator faces back??? SO which is it??

demian5 · 06-20-2018, 06:07 PM

Quote:

Originally Posted by hotwls13

Old thread but just read this. I have a 350 (according to PAN) and the Vacuum modulator faces back??? SO which is it??

Yeah.... both clues tell you its a 350...

hotwls13 · 06-20-2018, 06:14 PM

Quote:

Originally Posted by demian5

Yeah.... both clues tell you its a 350...

It say's "TH400 Vacuum modulator faces back"

Unless I'm looking at it wrong, my 350 modulator faces BACK??

geezer#99 · 06-20-2018, 06:42 PM

It doesn’t.
He was wrong.
Turbo 350 faces back.
Yours does.

02-11-2008, 09:18 AM	#1
Chevy1972/GMC2000 Registered User Join Date: Feb 2008 Location: British Columbia, Canada Posts: 8	how to tell a th350 from a th400 I was just woundering if someone could tell me how to tell a turbo350 from a turbo400 trans. My trucks trans is option coded as a M49, what trans is that? __________________ 1972 k10 chevy lwb project. 2000 gmc 1500 4x4 reg/long

02-11-2008, 09:39 AM	#2
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,634	Re: how to tell a th350 from a th400 Looking at the shape of the pan is the easiet way. Attached Images __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!

02-11-2008, 11:28 AM	#3
cruiserman Registered User Join Date: Dec 2006 Location: Idaho Posts: 210	Re: how to tell a th350 from a th400 400 oil pan is shaped like Texas. __________________ 72 C2500 LWB 402 Sierra Grande 05 Odyssey 08 Tundra

02-11-2008, 01:08 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: how to tell a th350 from a th400 quick and easy; kick down cable = TH350 No kickdown cable = TH400

02-11-2008, 04:23 PM	#5
68350 Senior Member Join Date: Jan 2002 Location: Williston, ND Posts: 2,999	Re: how to tell a th350 from a th400 nother quick way, th400-6 bolts in the tail housing th350-4 bolts __________________ 68 Chevy CST/10, 50th Anniversary, 327/th400, 373 posi, buckets 68 GMC Shortbox Stepside, 402/th400, Tilt, Tach, Bucket Seats, 3.08 Positraction 69 Chevy Camaro SS, 383, 4 speed, positraction 70 Chevy El Camino SS396, Triple Black, 454/th400, Tach 70 Chevy Shortbox Stepside 4x4, 350/th350, Tilt, Tach, Cab Lights, Bumper Guards, Tow Hooks 70 Chevy 3/4 Longbox, 350/auto, 70k, SURVIVOR 71 Chevy Blazer, CST, 350/auto 71 GMC Sierra K2500, 454, 4 speed, 4.10 posi, 37s 71 Custom/30, Open Road, 350/th400, tilt 72 Chevy Shortbox Fleetside, 496 Stroker/th400, Tilt, Tach, Bucket Seats, 3.42 Posi 72 GMC Sierra Grande 2500. 427/th400, tilt, a/c, tool and stowage, buckets/console, 3.54 posi

02-11-2008, 04:30 PM	#6
Machinist1972 Registered User Join Date: Feb 2008 Location: Langley B.C. Posts: 38	Re: how to tell a th350 from a th400 The top right transmission in the picture is a turbo 400 transmission. I look to see where the modulator valve is. It should be on the passenger side closer to the front when looking at the transmission from the back.

02-11-2008, 04:32 PM	#7
BLE 'BURBAN In the Forgotten far North. Join Date: Jul 2007 Location: Anchorage, Alaska Posts: 2,627	Re: how to tell a th350 from a th400 TH350 vacuum modulator faces right TH400 Vacuum modulator faces back __________________ 1987 R3500 CREW CAB DUALLY (BIG RED)Acquired 06/12/2015 1990 chevy suburban V2500 5.7L My cluster Mods-Nov 2007 overhead console Stereo install Round 2 Aug 2009 Heated/turn signal mirror upgrade

02-11-2008, 05:42 PM	#8
72armyswbtruck Registered User Join Date: Feb 2004 Location: Idaho Posts: 4,034	Re: how to tell a th350 from a th400 Boy look at all those ways to tell the difference __________________ "Remember, They can Kill You, but they can't eat You, That's against the law!!!!!!!!!"

02-11-2008, 05:56 PM	#9
blukangoo Neighborhood Pickle Slinger Join Date: Jan 2007 Location: Cadolzburg, Bavaria, Germany Posts: 2,224	Re: how to tell a th350 from a th400 Just like everyone else said: TH350 has a Mechanical (cable) Detent Cable. TH400 has an Electrical Detent Switch. Easiest way is the shape of the drainpan. Attached Images __________________ -------------------------------------------------- My C10 Diary Our cars: 1966 Chevrolet Chevelle 396 - TH350 1968 Chevrolet C10/CST 327 TH400/375 1969 Corvette Stingray 350 - Muncie Manual Trans 1969 Chevrolet ElCamino 350 - TH400 1970 Cutlass Supreme Convertible - 350 Rocket - TH350 1973 Camaro LT - New Engine Done - TH350 1973 Corvette Convertible 454 - TH400

12-01-2010, 11:52 PM	#10
LostMy65 But Found Her 25yrs Later! Join Date: Oct 2010 Location: Oregon City, Oregon Posts: 10,468	Re: how to tell a th350 from a th400 Thanks for this thread. I now know I have a 350. __________________ I lost my 65 - Found it 25 years later: http://67-72chevytrucks.com/vboard/s...d.php?t=426650 66 C20 Service Truck: http://67-72chevytrucks.com/vboard/s...d.php?t=428035

12-06-2010, 01:53 PM	#11
blukangoo Neighborhood Pickle Slinger Join Date: Jan 2007 Location: Cadolzburg, Bavaria, Germany Posts: 2,224	Re: how to tell a th350 from a th400 Cool to know that people still read threads that are 2 years old. __________________ -------------------------------------------------- My C10 Diary Our cars: 1966 Chevrolet Chevelle 396 - TH350 1968 Chevrolet C10/CST 327 TH400/375 1969 Corvette Stingray 350 - Muncie Manual Trans 1969 Chevrolet ElCamino 350 - TH400 1970 Cutlass Supreme Convertible - 350 Rocket - TH350 1973 Camaro LT - New Engine Done - TH350 1973 Corvette Convertible 454 - TH400

03-26-2012, 11:05 PM	#12
JointTech Registered User Join Date: Feb 2012 Location: Mission Viejo, CA Posts: 1,856	Re: how to tell a th350 from a th400 no 4 years old. I just found out i have a th400 Thanks. mmmm thread necro __________________ 72 C20 Long Bed SB350 TH400 14 bolt rear end Extremely boring build thread

09-17-2012, 02:57 PM	#13
dads longhorn Registered User Join Date: Mar 2010 Location: New mexico Posts: 369	Re: how to tell a th350 from a th400 Thanks for the thread, now I know I have a 350 TH. Is there a preference 350 vs 400? Thanks again

03-17-2013, 04:29 PM	#14
catch2otwo Registered User Join Date: Mar 2013 Location: SF Posts: 345	Re: how to tell a th350 from a th400 Anyone have a good recommendation of a deeper sump aluminum pan with a drain plug like the one pictured above?

03-17-2013, 08:28 PM	#16
Palf70Step State of Confusion! Join Date: Jul 2002 Location: Gulfport, MS USA Posts: 46,634	Re: how to tell a th350 from a th400 Here is what I used on MY T350 http://www.jegs.com/i/Hughes+Perform...FQzNnAodpGwAaQ __________________ Bill 1970 Chevy Custom/10 LWB Fleetside 2010 Toyota Tacoma PreRunner SR5 Double Cab - DD Member of Louisiana Classic Truck Club (LCTC) Bill's Gallery Life isn't tied with a bow, but it's still a gift. Live simply. Love generously. Care deeply. Speak kindly. Leave the rest to God!



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08-22-2016, 05:26 PM	#17
mrsmith Registered User Join Date: Jul 2016 Location: Fresno ,Ca Posts: 8	Re: how to tell a th350 from a th400 I know this is a really old thread ,but it is still VERY useful to us that are not quite up to the level of some of you other guys . I figured out i have a TH350 thanks to this thread without breaking any kind of sweat. thank you everyone for sharing your knowledge.

02-04-2017, 04:55 PM	#20
Nachos82 Registered User Join Date: Feb 2007 Location: Central Florida Posts: 166	Re: how to tell a th350 from a th400 Right on fellas, and thanks blukangoo for the unmistakable picture of the two different pans. Yea, this thread is old as crap, but it's the first Google search result that appears when you do "how to tell th350 from th400" and it was worth my efforts to log into the site and surf around like old times. I got a camaro last month and was wondering if it had a th350 or th400. Figures the best truck forum out there had the answer to my question. Upon deep investigation, if I had only waited 7 more days I could have made this a 9 year spread from initial post to my reply. Oh well, guess nobody can be that awesome.

02-04-2017, 08:27 PM	#21
towbar Registered User Join Date: Jul 2012 Location: Marshall, NC....heart of the Appalachians.....aka, Gods country!! Posts: 537	Re: how to tell a th350 from a th400 another quick and easy......governor gear has a 4 bolt cover on a T400, a clip bail cover on a T350

06-20-2018, 06:42 PM	#25
geezer#99 Registered User Join Date: Aug 2009 Location: Bowser Posts: 13,512	Re: how to tell a th350 from a th400 It doesn’t. He was wrong. Turbo 350 faces back. Yours does.

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