Planning tranny swap.... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

69GMC910 · 07-01-2005, 06:53 PM

I will be dropping in a 406 in my truck in the near future. My current tranny is the original powerglide that is tired and simply boring. My problem is I can't decide between a th350 or the th400. The engine puts out upwards of 470hp and 520 ft.lbs so I want something that can handle what i put to it. Does anyone run this kind of power and if you do, what is your setup???

910

69 longhorn · 07-01-2005, 07:25 PM

IMO, there is only 1 auto trans to run in the hypo app.....that would be the bad @ss 400 turbo hydro! it will take 18-20 more ponies @ the rear wheels to run, buit a good stock rebuild, + shift kit & converter to match your cam...should handle all the power/tork you are looking to give it

L

69 Short Fleet · 07-01-2005, 08:39 PM

Are you for sure going with an automatic? I have a granny 4 speed in mine and would like to upgrade to a T-56 (6 speed) later on, its a bit of work to get one in but ... just a thought, Doug

69GMC910 · 07-01-2005, 10:19 PM

The last thing I want is to blow up a tranny, would a th350 need a fair amount of cash dumped into it to handle the power?? Also, what are your opinions on 700r4's? Is the lock-up converter an issue? Is it as strong as the th400? How many RWHP does it require to run???? Fill me in!!

910

QKENUF4U · 07-02-2005, 12:14 AM

TH-400 all the way

GMC AMI · 07-02-2005, 05:27 AM

400's are stronger, a good 350 turbo handled my 455 Stage 1 Buick built with cam, highrise and roller rockers thru 2 years of drag racing and street driving with 0 problems!

Huck · 07-02-2005, 07:41 AM

A good Turbo 350 is stronger then most 700R4's and a Turbo 400 is about the best heavy duty auto you can get. It does not have an overdrive but that is about it's only shortcoming.

cdowns · 07-02-2005, 08:17 AM

you should go for a performance rebuild weather you decide on a 3speed or a 4speed overdive is just a matter of budget and how you intend to use the truck. a good place for bullitproof performance trannies is www.fbperformance.com

**dennislbrooks** · 07-02-2005, 08:52 AM

I would take a good look at a 700R4 like a B&M. If you plan to cruise at all the overdrive has better economy, will place less wear and tear, and does not suck down 20 ponies and weigh more like a 400 turbo. A good 350 heavy duty built should be considered. I run a GV overdrive ( uses 1 hp) behind my 350 turbo --however, I run a small block.

Call some of the professionals.

Long Roof · 07-02-2005, 08:25 PM

4l80e is an overdrive 400 basicly. They are a little hard to come by though. I would go with a good 400 and then take a look at Gear Venders over drive unit.

Aaron

07-01-2005, 06:53 PM	#1
69GMC910 MOTORHEAD! Join Date: May 2000 Location: Devon AB, Canada Posts: 849	Planning tranny swap.... I will be dropping in a 406 in my truck in the near future. My current tranny is the original powerglide that is tired and simply boring. My problem is I can't decide between a th350 or the th400. The engine puts out upwards of 470hp and 520 ft.lbs so I want something that can handle what i put to it. Does anyone run this kind of power and if you do, what is your setup??? 910 __________________ 82 GMC High Sierra VortecPro 496 12 Bolt, 3.42's AFR 265 Holley 850 Performer RPM Air Gap Hooker 2455's TCI Turbo 400 Super Street Fighter TRRC 12 Bolt Eaton Posi Mark Williams Axles Cal-Tracs Hoosier 30x10.5 Radial Slick Full weight long box pickup Current best- 11.33@117mph

07-01-2005, 07:25 PM	#2
69 longhorn Registered User Join Date: Aug 2001 Location: rock island,il,usa Posts: 5,382	IMO, there is only 1 auto trans to run in the hypo app.....that would be the bad @ss 400 turbo hydro! it will take 18-20 more ponies @ the rear wheels to run, buit a good stock rebuild, + shift kit & converter to match your cam...should handle all the power/tork you are looking to give it L __________________ http://community.webshots.com/user/hotrodhorn

07-01-2005, 10:19 PM	#4
69GMC910 MOTORHEAD! Join Date: May 2000 Location: Devon AB, Canada Posts: 849	The last thing I want is to blow up a tranny, would a th350 need a fair amount of cash dumped into it to handle the power?? Also, what are your opinions on 700r4's? Is the lock-up converter an issue? Is it as strong as the th400? How many RWHP does it require to run???? Fill me in!! 910 __________________ 82 GMC High Sierra VortecPro 496 12 Bolt, 3.42's AFR 265 Holley 850 Performer RPM Air Gap Hooker 2455's TCI Turbo 400 Super Street Fighter TRRC 12 Bolt Eaton Posi Mark Williams Axles Cal-Tracs Hoosier 30x10.5 Radial Slick Full weight long box pickup Current best- 11.33@117mph

07-02-2005, 05:27 AM	#6
GMC AMI Registered User Join Date: Apr 2004 Location: The Other Maine! Posts: 2,236	400's are stronger, a good 350 turbo handled my 455 Stage 1 Buick built with cam, highrise and roller rockers thru 2 years of drag racing and street driving with 0 problems! __________________ 1968 Chevy 4x4 307 4 speed

07-02-2005, 08:17 AM	#8
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	you should go for a performance rebuild weather you decide on a 3speed or a 4speed overdive is just a matter of budget and how you intend to use the truck. a good place for bullitproof performance trannies is www.fbperformance.com __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

07-01-2005, 08:39 PM	#3
69 Short Fleet Registered User Join Date: Nov 2002 Location: Kelowna B.C. Canada Posts: 1,086	Are you for sure going with an automatic? I have a granny 4 speed in mine and would like to upgrade to a T-56 (6 speed) later on, its a bit of work to get one in but ... just a thought, Doug

07-02-2005, 12:14 AM	#5
QKENUF4U Senior Member Join Date: Jan 2005 Location: SUNNY WARM BIKE RIDING COTTONWOOD ARIZONA Posts: 2,097	TH-400 all the way

07-02-2005, 07:41 AM	#7
Huck Senior Member Join Date: Jun 2001 Location: Shelbyville, KY Posts: 3,269	A good Turbo 350 is stronger then most 700R4's and a Turbo 400 is about the best heavy duty auto you can get. It does not have an overdrive but that is about it's only shortcoming.

07-02-2005, 08:52 AM	#9
dennislbrooks Senior Member Join Date: Feb 2004 Location: Williamsburg, Ohio Posts: 1,766	options I would take a good look at a 700R4 like a B&M. If you plan to cruise at all the overdrive has better economy, will place less wear and tear, and does not suck down 20 ponies and weigh more like a 400 turbo. A good 350 heavy duty built should be considered. I run a GV overdrive ( uses 1 hp) behind my 350 turbo --however, I run a small block. Call some of the professionals.

07-02-2005, 08:25 PM	#10
Long Roof Old School, New Style Join Date: Jun 2005 Location: Monroeville, Ohio Posts: 790	4l80e is an overdrive 400 basicly. They are a little hard to come by though. I would go with a good 400 and then take a look at Gear Venders over drive unit. Aaron __________________ The Good: - 72 GMC Jimmy 4x4 - 307 cid / 350 th - 70 Chevy Suburban 1/2T 2wd - 454 cid /400 th - 96 Chevy Impala SS - mainly stock - 98 Chevy Tahoe LT 4x4 - all stock The Bad: - 86 Chevy Suburban 1/2T 4x4 - winter beater The Ugly: - 72 Chevy Suburban 1/2T 2wd - parts truck



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