Which Turbo 400 to install???? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

gangforward · 07-06-2003, 09:53 PM

I'm finally ready to replace theh old powerglide with a turbo 400. The motor is going to be a 383 with heads, cam, headers, etc, so have decided to go with the brute.

Question - I know that all 400's are not the same. Which one should I look for? and what should I expect to pay for one?

Suggestions on where to get one, what model, etc are all appreciated!!

TIA!

72addict · 07-06-2003, 11:35 PM

I have a '72 400 turbo for sale. $100 + shipping

gangforward · 07-07-2003, 02:48 PM

Any idea of shipping costs? Which kind of 400 is it? Thanks.

Longhorn Man · 07-07-2003, 03:28 PM

As far as I know, a 400 is a 400 with the exception of tail shaft length.
Please some one correct me if I am wrong.

Jwill41 · 07-07-2003, 03:43 PM

I too have always thought there was only one except for the tail shafts.

07-07-2003, 05:39 PM

Thats depends if you want one from a Chevy, buick, or a few others I thought. I cant be for sure, but I thought there are more then one kind out there...... But aren't they still going to be the same?

Class of 69 · 07-07-2003, 06:02 PM

Only the bell housing area of the casting is different on the Olds, and Buick to accomodate the engine design. All internall dimensions are the same. The ones that came from the factory behind the hi-perf engines, did have different clutch packs with more plates in them. Any of them can be upgraded to the better clutchs. -

jef5150 · 07-07-2003, 06:18 PM

i guess if you want to upgrade it, you could go with an aftermarket torque converter,&shift kit

Longhorn Man · 07-07-2003, 06:29 PM

Well, I was ignoring the BOP bellhousing, the Chevy bellhousing was te odd ball in GM, Buick, Olds, pontiac, and Caddy all shared one, and chevy had another.

**COBALT** · 07-07-2003, 06:34 PM

There's some considerable differences in the older 400's ('65) that you probably won't find anyway. There are some subtle differences with the TH400s that came in trucks and cars between 1968 and 1980 in the valve body, the governor, some clutch components, and the modulator design.

Bottom line. If you get one out of a chevy truck (67-72) you're good to go.

da-burb · 07-07-2003, 11:43 PM

Have you totally tossed out the idea of a well built th350? It is a no brainer swap since you only have to bolt it in and go. No drive shaft to change and no crossmember to move, shift linkage is identical and no kick down switch to wire in. The other benefit is you will get more HP to the rear wheels with a little less weight to boot. I have been told you loose 10-20 hp with a th400 compared to a th350. Just an idea..........

GMC JUNKIE TOO · 07-08-2003, 01:46 AM

The only diffrence I know of is pre 69 models had a diffrent filter.

72addict · 07-08-2003, 03:58 AM

gangforward where is jackson? zip code? It is a stock shortshaft out of a 1972 c20

sniper2321 · 07-08-2003, 08:24 AM

the Cady version 69-71 actualy had strait cut planetary gear in it the model was the th475 version.

gangforward · 07-08-2003, 10:00 AM

Jackson, Wyoming - I'm planning on a pretty stout 383, with the idea I might put either a vortech supercharger or turbo's on it someday...

So I figured a T400 was the way to go.

**COBALT** · 07-08-2003, 12:36 PM

GMC JUNKIE TOO: You're thinking about 400's from '65. Not only are the filters different, but the pan and the valve body are different (pan is identifiable due to bulge to accomodate the can style filter). The front pump is also different in that year - plus the torque converter didn't have fixed stator blades. There are also differences in the governor, clutch drums, sprag clutches, etc. As I said considerable differences, but you'll have a hard time finding one of those anyway.

Since cases are radically different from maker to maker (and so are the tailhousings: there are three different types, but interchanged between makers) chances are you wouldn't want to interchange hard parts anyway (without knowing a hell of a lot about 400's), so as long as you end up with a transmission with a Chevy case (the classic triangle shaped bell housing) you shouldn't have to worry about the planetary assemblies, clutch packs, input/output shaft differences. Just make sure it came out of a Chevy truck.

beautimus · 07-08-2003, 02:03 PM

as far as the 400 is a 400 is a 400 question,
hot rod magazine had an article several years back about adapting a buick, olds or pontiac turbo 400 to a chevy block.
it used 2 small fabricated adapters at the top. it seems that
the line up pins are already in the correct place as are the
bottom 4 bolt holes. the article cautioned about using one from
a buick because they used a weird dual pitch torque converter.
(please note, i have not tried this myself, but i do know
of a friend of the family who did, although he passed away several years ago.)

but i guess that it all comes down to the long or short tail version.

tom hand · 07-08-2003, 03:49 PM

I pretty sure the 475 was a motorhome transmission...I have one in an 84 pathfinder...it looks just like a 400

Fred T · 07-08-2003, 03:56 PM

beautimus, you're right. The lower bolts and pins are the same. I used to help with putting together demo derby cars. We would bolt them together, then make some hold-down tabs for the uppers. For some reason, we werent' to concerned about how long it would hold together!

Longhorn Man · 07-09-2003, 07:19 PM

The TH 475 was a front wheel drive tranny.

crazy longhorn · 07-09-2003, 07:39 PM

Andy, the 425 hydro was a front drive trans. The 475 was found in the motor homes, & step vans. The 475 is basically a "tough 400 turbo(extra clutches, & straight cut planetery gears ..... a little whine in the lower gears(me likes that

) crazyL rowin 6

Longhorn Man · 07-09-2003, 08:15 PM

The only 475 I have ever heard of was in the Front wheel drive GMC motor homes.
And when that site said the TH 475 was a HD front wheel drive tranny, i figured it was right.
Cool, thanks.

crazy longhorn · 07-09-2003, 08:41 PM

Yup, I bet thats "square" . The GMC front drive motorhomes no doubt had the heavy trans. The Eldo & Toronado were a 425 hydro(just a twisted version of the 400). I wish I had more info on the 475T, I think I have 1 on the floor. The tell tale is the 6 lug allison converter. i havent opened the thing up to check the rest of the "goodies" tho crazyL

07-06-2003, 09:53 PM	#1
gangforward Hootis is as Hootis does... Join Date: Nov 2002 Location: Southern Georgia Posts: 500	Which Turbo 400 to install???? I'm finally ready to replace theh old powerglide with a turbo 400. The motor is going to be a 383 with heads, cam, headers, etc, so have decided to go with the brute. Question - I know that all 400's are not the same. Which one should I look for? and what should I expect to pay for one? Suggestions on where to get one, what model, etc are all appreciated!! TIA! __________________ 67 C10 LWB Fleet, 383, TH400, PS, 4BL-Holley, Headers & 3" Exhaust, 3" drop front, 4" rear springs, ECI shock relocate, Panhard Bar kit, wheels & tires 1995 Z28 Convertible - Borla, K&N, Lingenfelter Motor, C6 Wheels & Tires 1990 2500 4x4 Suburban 3" Catbac System, K&N, 2" Lift, Wheels, Tires

07-06-2003, 11:35 PM	#2
72addict Registered User Join Date: Mar 2000 Location: Mason MI, 48854 (strikezone of the mitten) Posts: 894	I have a '72 400 turbo for sale. $100 + shipping __________________ 1957 Cameo

07-07-2003, 02:48 PM	#3
gangforward Hootis is as Hootis does... Join Date: Nov 2002 Location: Southern Georgia Posts: 500	Any idea of shipping costs? Which kind of 400 is it? Thanks. __________________ 67 C10 LWB Fleet, 383, TH400, PS, 4BL-Holley, Headers & 3" Exhaust, 3" drop front, 4" rear springs, ECI shock relocate, Panhard Bar kit, wheels & tires 1995 Z28 Convertible - Borla, K&N, Lingenfelter Motor, C6 Wheels & Tires 1990 2500 4x4 Suburban 3" Catbac System, K&N, 2" Lift, Wheels, Tires

07-07-2003, 03:43 PM	#5
Jwill41 Registered User Join Date: Aug 2002 Location: Farmers Branch, Tx Posts: 1,009	I too have always thought there was only one except for the tail shafts. __________________ http://www.picturetrail.com/jwill41 67 1/2 ton GMC short step side 68 1/2 ton Chevy long fleet side 72 1/2 ton Chevy Suburban 99 1/2 ton Chevy Suburban founder (and only member) of the primer/clearcoat club

07-07-2003, 06:02 PM	#7
Class of 69 Registered User Join Date: Mar 2003 Location: Stillwater MN Posts: 1,166	Only the bell housing area of the casting is different on the Olds, and Buick to accomodate the engine design. All internall dimensions are the same. The ones that came from the factory behind the hi-perf engines, did have different clutch packs with more plates in them. Any of them can be upgraded to the better clutchs. - __________________ 69 GMC K10 ..some restoration required....still..

07-07-2003, 03:28 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	As far as I know, a 400 is a 400 with the exception of tail shaft length. Please some one correct me if I am wrong.

07-07-2003, 05:39 PM	#6
Linus0014 Guest Posts: n/a	Thats depends if you want one from a Chevy, buick, or a few others I thought. I cant be for sure, but I thought there are more then one kind out there...... But aren't they still going to be the same?

07-07-2003, 06:18 PM	#8
jef5150 Inline 69 Join Date: Apr 2003 Location: valleysprings,california Posts: 1,018	i guess if you want to upgrade it, you could go with an aftermarket torque converter,&shift kit

07-07-2003, 06:29 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Well, I was ignoring the BOP bellhousing, the Chevy bellhousing was te odd ball in GM, Buick, Olds, pontiac, and Caddy all shared one, and chevy had another.

07-07-2003, 06:34 PM	#10
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	There's some considerable differences in the older 400's ('65) that you probably won't find anyway. There are some subtle differences with the TH400s that came in trucks and cars between 1968 and 1980 in the valve body, the governor, some clutch components, and the modulator design. Bottom line. If you get one out of a chevy truck (67-72) you're good to go. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

07-07-2003, 11:43 PM	#11
da-burb "Ochre Ogre" Join Date: Apr 2000 Location: Springfield, MN Posts: 3,558	Have you totally tossed out the idea of a well built th350? It is a no brainer swap since you only have to bolt it in and go. No drive shaft to change and no crossmember to move, shift linkage is identical and no kick down switch to wire in. The other benefit is you will get more HP to the rear wheels with a little less weight to boot. I have been told you loose 10-20 hp with a th400 compared to a th350. Just an idea.......... __________________ Bowtie Truck Stop Inc. Mid-West GM Truck Restoration Parts Supplier Your Key Parts, Auto Metal Direct, Dynacorn, and Goodmark dealer. like us @ www.facebook.com/BowtieTruckStop 1971 C-10 Suburban (Ochre) 1971 K-10 Suburban (Ochre) 1972 C-10 Suburban (Ochre) 1972 K-20 Suburban (Yellow- that just aint right!) Springfield, Minnesota 56087

07-08-2003, 01:46 AM	#12
GMC JUNKIE TOO THE QUICKER FIXERUPER Join Date: Jul 2002 Location: Ok Posts: 615	The only diffrence I know of is pre 69 models had a diffrent filter.

07-08-2003, 03:58 AM	#13
72addict Registered User Join Date: Mar 2000 Location: Mason MI, 48854 (strikezone of the mitten) Posts: 894	gangforward where is jackson? zip code? It is a stock shortshaft out of a 1972 c20 __________________ 1957 Cameo

07-08-2003, 08:24 AM	#14
sniper2321 Registered User Join Date: May 2002 Location: S.E. Fla Posts: 185	the Cady version 69-71 actualy had strait cut planetary gear in it the model was the th475 version.

07-08-2003, 10:00 AM	#15
gangforward Hootis is as Hootis does... Join Date: Nov 2002 Location: Southern Georgia Posts: 500	Jackson, Wyoming - I'm planning on a pretty stout 383, with the idea I might put either a vortech supercharger or turbo's on it someday... So I figured a T400 was the way to go. __________________ 67 C10 LWB Fleet, 383, TH400, PS, 4BL-Holley, Headers & 3" Exhaust, 3" drop front, 4" rear springs, ECI shock relocate, Panhard Bar kit, wheels & tires 1995 Z28 Convertible - Borla, K&N, Lingenfelter Motor, C6 Wheels & Tires 1990 2500 4x4 Suburban 3" Catbac System, K&N, 2" Lift, Wheels, Tires



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07-08-2003, 12:36 PM	#16
COBALT Senior Member Join Date: Sep 2001 Location: Seattle, WA, USA Posts: 5,817	GMC JUNKIE TOO: You're thinking about 400's from '65. Not only are the filters different, but the pan and the valve body are different (pan is identifiable due to bulge to accomodate the can style filter). The front pump is also different in that year - plus the torque converter didn't have fixed stator blades. There are also differences in the governor, clutch drums, sprag clutches, etc. As I said considerable differences, but you'll have a hard time finding one of those anyway. Since cases are radically different from maker to maker (and so are the tailhousings: there are three different types, but interchanged between makers) chances are you wouldn't want to interchange hard parts anyway (without knowing a hell of a lot about 400's), so as long as you end up with a transmission with a Chevy case (the classic triangle shaped bell housing) you shouldn't have to worry about the planetary assemblies, clutch packs, input/output shaft differences. Just make sure it came out of a Chevy truck. __________________ '69 3/4 ton C20 2wd-350ci/TH400 '69 3/4 ton Custom 20 2wd-350ci/4sp Manual '99 2wd 5.7 Chevy Tahoe Seattle, WA.

07-08-2003, 02:03 PM	#17
beautimus Registered User Join Date: Mar 2002 Location: woodstock, alabama, usa Posts: 938	as far as the 400 is a 400 is a 400 question, hot rod magazine had an article several years back about adapting a buick, olds or pontiac turbo 400 to a chevy block. it used 2 small fabricated adapters at the top. it seems that the line up pins are already in the correct place as are the bottom 4 bolt holes. the article cautioned about using one from a buick because they used a weird dual pitch torque converter. (please note, i have not tried this myself, but i do know of a friend of the family who did, although he passed away several years ago.) but i guess that it all comes down to the long or short tail version. __________________ i survived cancer and kidney stones, but my kids are killing me.

07-08-2003, 03:49 PM	#18
tom hand CCRider Join Date: Feb 2000 Location: Olive Branch,MS,USA Posts: 2,232	I pretty sure the 475 was a motorhome transmission...I have one in an 84 pathfinder...it looks just like a 400 __________________ 72 GMC Sierra SWB almost finished---- 84 Softail Olive Branch MS

07-08-2003, 03:56 PM	#19
Fred T Cantankerous Geezer Join Date: Aug 2002 Location: Bel Aire, KS Posts: 6,264	beautimus, you're right. The lower bolts and pins are the same. I used to help with putting together demo derby cars. We would bolt them together, then make some hold-down tabs for the uppers. For some reason, we werent' to concerned about how long it would hold together! __________________ Fred There is no such thing as too much cam...just not enough engine.

07-09-2003, 07:19 PM	#20
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	The TH 475 was a front wheel drive tranny.

07-09-2003, 07:39 PM	#21
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	Andy, the 425 hydro was a front drive trans. The 475 was found in the motor homes, & step vans. The 475 is basically a "tough 400 turbo(extra clutches, & straight cut planetery gears ..... a little whine in the lower gears(me likes that ) crazyL rowin 6 __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

07-09-2003, 08:15 PM	#22
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	The only 475 I have ever heard of was in the Front wheel drive GMC motor homes. And when that site said the TH 475 was a HD front wheel drive tranny, i figured it was right. Cool, thanks.

07-09-2003, 08:41 PM	#23
crazy longhorn Fabricate till you "puke" Join Date: Jun 2002 Location: Ill Posts: 9,403	Yup, I bet thats "square" . The GMC front drive motorhomes no doubt had the heavy trans. The Eldo & Toronado were a 425 hydro(just a twisted version of the 400). I wish I had more info on the 475T, I think I have 1 on the floor. The tell tale is the 6 lug allison converter. i havent opened the thing up to check the rest of the "goodies" tho crazyL __________________ 69 longhorn,4" chop,3/5 drop, 1/2 ton suspension/disc brakes,1 1/2" body drop,steel tilt clip, 5.3/Edelbrock rpm intake/600 carb, Hooker streetrod shorties,2 1/2" exhaust/ H pipe/50's Flows , 6 spd Richmond trans,12 bolt/ 3.40 gears....

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