Correct Tailshaft length T-350?... - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Fasglas · 06-03-2006, 06:57 AM

I have a 1968 Chevy short wheelbase PU with no motor or transmission. I have a 350ci sbc for it now and was planning on using a Turbo 350 transmission. What is the correct tailshaft length T-350 that would have come in this truck?

Thanks!
Chris

Sweet72 · 06-03-2006, 08:29 AM

I have the 6" tailshaft in my '72 swb GMC.

NewKid · 06-03-2006, 10:44 AM

Good Morning, I think the th400 came in that truck, Why don't you want to use it? It is a far stronger transmission. I think they had some problems with it up until 1978 when they finally got it worked out. Most tranny shops can build out any problem areas. From what I can see is that the th350 with the 6" will be about 9/16" shorter then the th400 - C for overall length. The D length was 33 27/32" and the 13" was 37 7/8" long.

Longhorn Man · 06-03-2006, 04:05 PM

New kid is right, the TH350 wasn't put in these trucks untill 69.
However, the 69 - 72 trucks DID in fact have the short shaft TH350.
The TH350 is a perfectly good tranny, and in stock form can handle some heavy use, however, the TH400 is in fact stronger, and if you beat the crap out of your rig, it could be a wise move. The strength doesn't come free though. I can't remember exact numbers, but the kilgore rating is considerably higher on the TH400. (kilgore rating indicates how much power is lost through friction and inefficent designs)

Fasglas · 06-04-2006, 10:16 AM

Thanks to eveyone who responded. My main objective is to use as many correct type parts so I won't run into problems with things like a custom length driveshaft. I have two Turbo 350s setting here one has a short tail shaft and the other has a spacer on the tail shaft which makes it longer. I have the driveshaft that came out of the truck and I'm hoping if I use the correct tailshaft length the driveshaft might fit with no mods (the truck had a T-350 in it when it last ran).

Does anyone know how long the driveshaft should be for a short shaft T-350 in a 1968 swb?

Thanks again,
Chris

Longhorn Man · 06-04-2006, 10:36 AM

4 foot 10 inches

Fasglas · 06-06-2006, 03:14 PM

Thanks again! This forum is great!

06-03-2006, 06:57 AM	#1
Fasglas Registered User Join Date: Mar 2004 Location: Oklahoma Posts: 28	Correct Tailshaft length T-350?... I have a 1968 Chevy short wheelbase PU with no motor or transmission. I have a 350ci sbc for it now and was planning on using a Turbo 350 transmission. What is the correct tailshaft length T-350 that would have come in this truck? Thanks! Chris

06-03-2006, 08:29 AM	#2
Sweet72 Registered User Join Date: Nov 2003 Location: Alexandria, VA Posts: 1,534	Re: Correct Tailshaft length T-350?... I have the 6" tailshaft in my '72 swb GMC. __________________ '72 GMC SWB C1500 Custom, frame-off in progress. 383 SBC, 9:1CR, Comp Cams XE262H, Scat internal balanced crank, Eagle SIR 6" rods, Keith Black dish pistons, Dart Iron Eagle 72/180 heads, Weiand Stealth intake, Stewart stage I water pump, Holley 4bbl vac sec, TH350 with B&M Shift Improver Kit. 12 bolt positraction.

06-03-2006, 10:44 AM	#3
NewKid Registered User Join Date: Aug 2005 Location: OCEAN SHORES WASHINGOTN Posts: 57	Re: Correct Tailshaft length T-350?... Good Morning, I think the th400 came in that truck, Why don't you want to use it? It is a far stronger transmission. I think they had some problems with it up until 1978 when they finally got it worked out. Most tranny shops can build out any problem areas. From what I can see is that the th350 with the 6" will be about 9/16" shorter then the th400 - C for overall length. The D length was 33 27/32" and the 13" was 37 7/8" long. __________________ 83 GMC Vandura 1 Ton 84 Chevy S-10 4x4 Durango 84 Ford 1 ton Cargo van Last edited by NewKid; 06-03-2006 at 10:48 AM.

06-03-2006, 04:05 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Correct Tailshaft length T-350?... New kid is right, the TH350 wasn't put in these trucks untill 69. However, the 69 - 72 trucks DID in fact have the short shaft TH350. The TH350 is a perfectly good tranny, and in stock form can handle some heavy use, however, the TH400 is in fact stronger, and if you beat the crap out of your rig, it could be a wise move. The strength doesn't come free though. I can't remember exact numbers, but the kilgore rating is considerably higher on the TH400. (kilgore rating indicates how much power is lost through friction and inefficent designs)

06-04-2006, 10:16 AM	#5
Fasglas Registered User Join Date: Mar 2004 Location: Oklahoma Posts: 28	Re: Correct Tailshaft length T-350?... Thanks to eveyone who responded. My main objective is to use as many correct type parts so I won't run into problems with things like a custom length driveshaft. I have two Turbo 350s setting here one has a short tail shaft and the other has a spacer on the tail shaft which makes it longer. I have the driveshaft that came out of the truck and I'm hoping if I use the correct tailshaft length the driveshaft might fit with no mods (the truck had a T-350 in it when it last ran). Does anyone know how long the driveshaft should be for a short shaft T-350 in a 1968 swb? Thanks again, Chris

06-04-2006, 10:36 AM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Correct Tailshaft length T-350?... 4 foot 10 inches

06-06-2006, 03:14 PM	#7
Fasglas Registered User Join Date: Mar 2004 Location: Oklahoma Posts: 28	Re: Correct Tailshaft length T-350?... Thanks again! This forum is great!



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