454 bolted to a th350 Tranny Question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**Canadian694x4** · 11-29-2004, 11:57 PM

Would you trust this combo as a daily driver? I seem to recall th400 is better suited to handle the power of a big block. Any possible issues you can share?

Thanks,

Brian

Longhorn Man · 11-30-2004, 12:03 AM

If you are talkin about a stock engine...sure, it'll hold up.
If it is a hot rod motor, It'll hold, but not for 100,000 miles.

race-n-jason · 11-30-2004, 12:11 AM

If the motor isn't too radically built, or you don't plan on drag racing on a regular basis, a T350 should be just fine. I have put alot of miles on mine. My motor is only mildly built. I did have my tranny rebuilt a couple years ago while I was rebuiding the motor. For good measure, I had a heavy duty intermediate sprag installed, along w/ a shift kit. Wasn't totally necessary, though.

**Canadian694x4** · 11-30-2004, 01:07 AM

Engine has a mild cam...some type of shift kit in the TH350 tho...this is also in a 3/4 ton 4x4...any other thoughts?

Tx Firefighter · 11-30-2004, 08:34 AM

Simply put, your right foot will determine the transmissions life span.

If you flog it, it will probably die sooner. If you treat it with repsect, and don't beat on it, it should live as long as the engine does.

I can run a big block with a TH350 for the rest of my life and not hurt it. I drive my stuff with respect.

'71c204x4454 · 11-30-2004, 02:40 PM

I run a th350 behind mine with out any problems. If you are doing any towing or heavy hauling I would put a good tranny cooler in.

junkyardjohn · 11-30-2004, 03:03 PM

GENERAL MOTORS HAS NEVER SOLD A NEW VEHICAL WITH A BIG BLOCK IN IT & A TURBO 350 BEHIND IT. A T-350 CAN BE BUILT (FOR CONSIDERABLE EXPENSE) TO HOLD UP TO A BIG BLOCK, BUT WHY?? T-400s ARE NOT HARD TO COME BY, & ARE ABOUT THE SAME PRICE TO REBUILD. EXCEPT FOR A RACING APLICATIONS (T-350s ARE ABOUT 70 LBS LIGHTER) I CAN'T THINK OF A SINGLE REASON.

JOHN

**1970 CST Short Wide** · 11-30-2004, 04:13 PM

How about "because thatâ€™s whatâ€™s in there now and I just had it rebuiltâ€ Thatâ€™s my story and I'm sticking too it. I'm hopeing to put my new 454 in by end of Dec.. I'll most likely keep my eye open for a 400 core just in case my foot gets heavier playing with the new found torque LOL.

sdmahr · 11-30-2004, 04:56 PM

Run it ! ! TH350's have been used and abused with a tremendous amount of success. If it craps out, then worry about getting a 400.

Hey man....if it ain't broke, don't fix it !

**Canadian694x4** · 11-30-2004, 07:58 PM

Quote:

Originally Posted by '71c204x4454

I run a th350 behind mine with out any problems. If you are doing any towing or heavy hauling I would put a good tranny cooler in.

For the record there is a truck I'm checking out. Has heavy duty everything, 454 engine, Dana 60's front and back...yet the 350 tranny and no mention of a tranny cooler.

In his ad and emails to me he said it was built to haul wood and tow a car trailer. He has 68,000 miles on it too date, should I be worried how he treated it? How much more life can I expect?

He wants a pretty penny for it and I'm tryin' to figure out if I wanna shell out the $$$ then ultimately have to replace what could be seen as "cutting corners".

Thanks

Brian

Longhorn Man · 11-30-2004, 09:30 PM

The TH350 is a tough SOB. It is stronger than a 700 R4...and no one sems to worry about them.
Check the tranny like you would regardless of the engine....fluid color, smell, taste, how long does it take to go into gear when the lever is move, funny noises...

gregsplace · 11-30-2004, 09:58 PM

Quote:

Originally Posted by junkyardjohn

GENERAL MOTORS HAS NEVER SOLD A NEW VEHICAL WITH A BIG BLOCK IN IT & A TURBO 350 BEHIND IT. A T-350 CAN BE BUILT (FOR CONSIDERABLE EXPENSE) TO HOLD UP TO A BIG BLOCK, BUT WHY?? T-400s ARE NOT HARD TO COME BY, & ARE ABOUT THE SAME PRICE TO REBUILD. EXCEPT FOR A RACING APLICATIONS (T-350s ARE ABOUT 70 LBS LIGHTER) I CAN'T THINK OF A SINGLE REASON.

JOHN

Well...........here's my reason..........couldnt find or afford a T-400/205 setup when I switched my 3/4-4x4 BB to auto so I used a used T-350!!
I pull a '16 stock trailer loaded with 20 plus 250lb fat hogs, car trailer with trucks/cars on it, scarp iron loads, and last but not least, pulled trees and stumps out and have yet to burn my T-350 yet. BB is stock though. Truck has 33"s, 4.10 gear. On the 2 swb's BB I'm currently working on, I'm using T-400's only because I have them, if I didnt, I wouldnt hesitate using a T-350 if thats what I had. ....sorry so long...

**Canadian694x4** · 11-30-2004, 10:38 PM

Thanks for the input all! Love this Board!

**too much stuff** · 11-30-2004, 10:38 PM

Hey canadian, My truck is a 70 4x4 with a 402 BB/ turbo 350. Tranny was rebuilt approx 10 yrs ago, and big block want in about 8 years ago. No problems with the tranny ever. I pull a car trailer, 16' boat etc. Make sure fluid is changed and taken care of. Oh yeah, well over 320,000 miles on truck, but not sure how many on tranny and engine.

longhorn71 · 11-30-2004, 11:26 PM

Quote:

Originally Posted by junkyardjohn

GENERAL MOTORS HAS NEVER SOLD A NEW VEHICAL WITH A BIG BLOCK IN IT & A TURBO 350 BEHIND IT. A T-350 CAN BE BUILT (FOR CONSIDERABLE EXPENSE) TO HOLD UP TO A BIG BLOCK, BUT WHY?? T-400s ARE NOT HARD TO COME BY, & ARE ABOUT THE SAME PRICE TO REBUILD. EXCEPT FOR A RACING APLICATIONS (T-350s ARE ABOUT 70 LBS LIGHTER) I CAN'T THINK OF A SINGLE REASON.

JOHN

my wifes 396 longhorn has a th-350 from factory.The truck has about 400,000 miles on it trans is orginal but the front seal is leaking.

Longhorn Man · 12-01-2004, 12:11 AM

I was thinking I have seen a big block truck or two with TH350s claimed to be original in them.

11-29-2004, 11:57 PM	#1
Canadian694x4 Born To Lose Club Join Date: Feb 2003 Location: Calgary, Alberta/Oxenden, Ontario, Great White North Posts: 13,307	454 bolted to a th350 Tranny Question Would you trust this combo as a daily driver? I seem to recall th400 is better suited to handle the power of a big block. Any possible issues you can share? Thanks, Brian __________________ Brian Smith - "Born To Lose" 1969 Chevrolet K10 LWB Fleetside - Proud Owner For 22 Yrs - 1 of 208 Built & Sold In Canada!- 283 V8/350TH/NP208, 2" All Spring Lift, 32" Good Year MT/R's. 1972 GMC K2500 Custom LWB Fleetside - Proud Owner For 3 Yrs - 1 of 571 Built & Sold In Canada! - 350 V8/SM465/NP205, 4” Rough Country Lift, 33” Interco TSL Thornbirds 2007.5 GMC Sierra SLE 2500HD 4x4 - Proud Owner For 17 Yrs- 6.6L V8 Duramax Diesel/Allison 1000, 2" Lift, 33" Mickey Thompson MTZ's. 2008 Yamaha Raptor 700r - Proud Owner For 15 Yrs - ITP Mud Lites. 2015 John Deere 1025R - Proud Owner For 8 Yrs - 24HP Diesel/H120/54D/260B/SB1154.

11-30-2004, 12:11 AM	#3
race-n-jason -Praise the Lowered- Join Date: Oct 2001 Location: Garland, Tx, USA Posts: 280	If the motor isn't too radically built, or you don't plan on drag racing on a regular basis, a T350 should be just fine. I have put alot of miles on mine. My motor is only mildly built. I did have my tranny rebuilt a couple years ago while I was rebuiding the motor. For good measure, I had a heavy duty intermediate sprag installed, along w/ a shift kit. Wasn't totally necessary, though. __________________ Race-N-Jason ('71 Chevy C-10 LWB 454/TH350) ('07 Dodge Ram 2500, 5.9 Cummins/6-speed Manual)

11-30-2004, 01:07 AM	#4
Canadian694x4 Born To Lose Club Join Date: Feb 2003 Location: Calgary, Alberta/Oxenden, Ontario, Great White North Posts: 13,307	Engine has a mild cam...some type of shift kit in the TH350 tho...this is also in a 3/4 ton 4x4...any other thoughts? __________________ Brian Smith - "Born To Lose" 1969 Chevrolet K10 LWB Fleetside - Proud Owner For 22 Yrs - 1 of 208 Built & Sold In Canada!- 283 V8/350TH/NP208, 2" All Spring Lift, 32" Good Year MT/R's. 1972 GMC K2500 Custom LWB Fleetside - Proud Owner For 3 Yrs - 1 of 571 Built & Sold In Canada! - 350 V8/SM465/NP205, 4” Rough Country Lift, 33” Interco TSL Thornbirds 2007.5 GMC Sierra SLE 2500HD 4x4 - Proud Owner For 17 Yrs- 6.6L V8 Duramax Diesel/Allison 1000, 2" Lift, 33" Mickey Thompson MTZ's. 2008 Yamaha Raptor 700r - Proud Owner For 15 Yrs - ITP Mud Lites. 2015 John Deere 1025R - Proud Owner For 8 Yrs - 24HP Diesel/H120/54D/260B/SB1154.

11-30-2004, 08:34 AM	#5
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	Simply put, your right foot will determine the transmissions life span. If you flog it, it will probably die sooner. If you treat it with repsect, and don't beat on it, it should live as long as the engine does. I can run a big block with a TH350 for the rest of my life and not hurt it. I drive my stuff with respect. __________________ I'm on the Instagram- @Gearhead_Kevin

11-30-2004, 02:40 PM	#6
'71c204x4454 '71k204x4454 Join Date: Jan 2004 Location: Hood River Or. Posts: 137	I run a th350 behind mine with out any problems. If you are doing any towing or heavy hauling I would put a good tranny cooler in. __________________ 1971 K20 4x4 1964 buick skylark convertible

11-30-2004, 12:03 AM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	If you are talkin about a stock engine...sure, it'll hold up. If it is a hot rod motor, It'll hold, but not for 100,000 miles.

11-30-2004, 03:03 PM	#7
junkyardjohn Registered User Join Date: Aug 2001 Location: SOMERSET KY. Posts: 6,425	GENERAL MOTORS HAS NEVER SOLD A NEW VEHICAL WITH A BIG BLOCK IN IT & A TURBO 350 BEHIND IT. A T-350 CAN BE BUILT (FOR CONSIDERABLE EXPENSE) TO HOLD UP TO A BIG BLOCK, BUT WHY?? T-400s ARE NOT HARD TO COME BY, & ARE ABOUT THE SAME PRICE TO REBUILD. EXCEPT FOR A RACING APLICATIONS (T-350s ARE ABOUT 70 LBS LIGHTER) I CAN'T THINK OF A SINGLE REASON. JOHN __________________ junkyardjohn 69 1 TON TOW TRUCK // 84 4WD CUCV BLAZER// 85 1 TON 4WD STAKE TRUCK// 86 M1031 5/4 TON 4WD CUCV// ALOT OF OLD TRUCKS FOR ONE OLD MAN TO DRIVE. THERES ROOM FOR ALL OF GODS CREATURES RIGHT NEXT TO MY MASHED POTATOES// LIFE MEMBER OF P.E.T.A (PEOPLE EATING TASTY ANIMALS) DON'T RENT U-HAUL ALWAYS TELL THE TRUTH IT WILL AMAZE PART OF THE PEOPLE & ASTONISH THE REST

11-30-2004, 04:13 PM	#8
1970 CST Short Wide Senior Moment Join Date: Mar 2002 Location: Pittsburg Ca Posts: 4,185	How about "because thatâ€™s whatâ€™s in there now and I just had it rebuiltâ€ Thatâ€™s my story and I'm sticking too it. I'm hopeing to put my new 454 in by end of Dec.. I'll most likely keep my eye open for a 400 core just in case my foot gets heavier playing with the new found torque LOL. __________________ 1970 CST LS 1 6 speed Ford 9 inch Detroit Tru Track, Dakota Didgital, Vintage Air, QA1 Coil Overs Front & Rear Lots of FUN 2013 GMC PU, Oldest Son 71 GMC LWB. QA1 Suspension, Angry SB. Youngest Son 2019 GMC Diesil Dually. Youngest Son 2017 Toyota SUV Daughters car 2018 Traverse , Wife’s Ride Pittsburg Ca 94565

11-30-2004, 04:56 PM	#9
sdmahr Registered User Join Date: Apr 2004 Location: South Texas....the Valley Posts: 199	Run it ! ! TH350's have been used and abused with a tremendous amount of success. If it craps out, then worry about getting a 400. Hey man....if it ain't broke, don't fix it !

11-30-2004, 09:30 PM	#11
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	The TH350 is a tough SOB. It is stronger than a 700 R4...and no one sems to worry about them. Check the tranny like you would regardless of the engine....fluid color, smell, taste, how long does it take to go into gear when the lever is move, funny noises...

11-30-2004, 10:38 PM	#13
Canadian694x4 Born To Lose Club Join Date: Feb 2003 Location: Calgary, Alberta/Oxenden, Ontario, Great White North Posts: 13,307	Thanks for the input all! Love this Board! __________________ Brian Smith - "Born To Lose" 1969 Chevrolet K10 LWB Fleetside - Proud Owner For 22 Yrs - 1 of 208 Built & Sold In Canada!- 283 V8/350TH/NP208, 2" All Spring Lift, 32" Good Year MT/R's. 1972 GMC K2500 Custom LWB Fleetside - Proud Owner For 3 Yrs - 1 of 571 Built & Sold In Canada! - 350 V8/SM465/NP205, 4” Rough Country Lift, 33” Interco TSL Thornbirds 2007.5 GMC Sierra SLE 2500HD 4x4 - Proud Owner For 17 Yrs- 6.6L V8 Duramax Diesel/Allison 1000, 2" Lift, 33" Mickey Thompson MTZ's. 2008 Yamaha Raptor 700r - Proud Owner For 15 Yrs - ITP Mud Lites. 2015 John Deere 1025R - Proud Owner For 8 Yrs - 24HP Diesel/H120/54D/260B/SB1154.

11-30-2004, 10:38 PM	#14
too much stuff Roadtrip! Join Date: Feb 2003 Location: Grand Rapids MN Posts: 13,787	Hey canadian, My truck is a 70 4x4 with a 402 BB/ turbo 350. Tranny was rebuilt approx 10 yrs ago, and big block want in about 8 years ago. No problems with the tranny ever. I pull a car trailer, 16' boat etc. Make sure fluid is changed and taken care of. Oh yeah, well over 320,000 miles on truck, but not sure how many on tranny and engine. __________________ 67 gmc custom lwb dakota truck. Sold...And bought back 69 swb 4x4 project (in progress) 70 c-10 lwb texas truck 70 4x4/BB/bkts/posi/tach(retired) 70 swb (wifes) 70 jimmy camper 71 K-5 factory 2wd 71 cheyenne 4x4/tach/posi/ plow rig 71 Cheyenne20 BB, buckets, tach, tilt, 4 speed 72 jimmy CST wyoming rig 72 jimmy Colorado rig 72 lifted texas 4x4 3/4 ton burb 65 fury conv. 383/auto 65 chrysler 300 "L" 413 auto

12-01-2004, 12:11 AM	#16
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	I was thinking I have seen a big block truck or two with TH350s claimed to be original in them.

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