Donor questions - The 1947 - Present Chevrolet & GMC Truck Message Board Network

East End K5 · 10-26-2011, 10:28 PM

Hello all, I'm back from alot of house work and ready to tackle some serious work to my rig. I recently bought a 1980 C30 cab and chassis, with a 454, TH400. I'm going to be pulling the cab, clip, engine, tranny, wheels and tires. My question is what is needed to stuff the 454 and tranny in my existing truck, to meet up with the transfer case, since my existing K35 has the 4WD. I believe I have a TH350 transmission. I will be swapping the cab, and clip since they are all solid too. Its gonna be a 1980 body with a 1986 K35 frame dually set up.

Thx!

**old Rusty C10** · 10-27-2011, 08:32 AM

anyone?

donut · 10-27-2011, 09:35 AM

If you have a tbh350 in the truck now, the easiest would be finding a 4x4 tbh400 and transfer case (and more than likely driveshafts) out of a junkyard.

The tbh350 is a 27 spline output, the tbh400 is 32 spline. AFAIK the existing transfer case won't work (in it's current form). The case can be reworked to fit to the tbh400, but you still need to get the adapter. Our 4x4's don't use long or short shaft like the 2wd, but go directly to an adapter then coupled to the transfer case.

I mention driveshafts because I believe that the tbh400 is physically longer than the tbh350.

I'm not an expert, I'm sure that someone with a ton more knowledge will chime in shortly.
At least I can give you some things to think about. I know it's not a direct swap, otherwise my old k-20 would have had the tbh400, instead of me having the tbh350 rebuilt. (I had both in the barn.)

The 454 will bolt right up to the tbh350, how long it will last is unknown.

East End K5 · 10-27-2011, 10:10 AM

Ok thx! I do in fact have the TH400 installed in my current truck so I don't have to worry any further with the drive shafts and connecting to the transfer case. The donor was a fire truck and has 60k on the 454...truck was garaged Tranny possibly needs a re-clutch. Engine is tight, no leaks, Rochester 4bl carb needs a deusching. Other than that the cab and clip will be swapped.
Posted via Mobile Device

donut · 10-27-2011, 10:08 PM

Sweet!, then I typed all that for nothing, lol

Have fun!

East End K5 · 10-28-2011, 12:08 PM

Ha ha.. Sorry about that! You'll be the last one laughing when I'm covered in grease and soot.... Pictures to follow for entertainment...
Posted via Mobile Device

10-26-2011, 10:28 PM	#1
East End K5 Registered User Join Date: Nov 2004 Location: Long Island NY Posts: 293	Donor questions Hello all, I'm back from alot of house work and ready to tackle some serious work to my rig. I recently bought a 1980 C30 cab and chassis, with a 454, TH400. I'm going to be pulling the cab, clip, engine, tranny, wheels and tires. My question is what is needed to stuff the 454 and tranny in my existing truck, to meet up with the transfer case, since my existing K35 has the 4WD. I believe I have a TH350 transmission. I will be swapping the cab, and clip since they are all solid too. Its gonna be a 1980 body with a 1986 K35 frame dually set up. Thx! __________________ I feel sorry for people who don't drink....because when they wake up in the morning, that's the best they're gonna feel all day long!---Frank Sinatra RIP [B]1972 Chevrolet K5 Blazer RIP 1986 GMC Sierra K3500 1TON, Long Box, V8350 RIP 1980 Chevy Silverado C30 Cab and Chassis, 454 TH400HD. RIP [B] 1995 Chevrolet Tahoe 2D [B]

10-27-2011, 08:32 AM	#2
old Rusty C10 Robert Olson Transport Join Date: Oct 2002 Location: recent transplant to NC USA Posts: 20,281	Re: Donor questions anyone? __________________ Bob 1951 International running on a squarebody chassis "If a man's worth is judged by the people he associates himself with, then i am the richest man in the world knowing some of the fine people of this board" http://67-72chevytrucks.com/vboard/a...t.php?f=25&a=9 (you can review the site rules here!) PM Me for your vehicle/parts hauling needs in the North East US or see my Facebook page Robert Olson Transport Live each day to the fullest.. you never know when fate is going to pull the rug out from under you... I hate cancer!!

10-27-2011, 09:35 AM	#3
donut Registered User Join Date: Aug 2009 Location: S.C. Posts: 1,593	Re: Donor questions If you have a tbh350 in the truck now, the easiest would be finding a 4x4 tbh400 and transfer case (and more than likely driveshafts) out of a junkyard. The tbh350 is a 27 spline output, the tbh400 is 32 spline. AFAIK the existing transfer case won't work (in it's current form). The case can be reworked to fit to the tbh400, but you still need to get the adapter. Our 4x4's don't use long or short shaft like the 2wd, but go directly to an adapter then coupled to the transfer case. I mention driveshafts because I believe that the tbh400 is physically longer than the tbh350. I'm not an expert, I'm sure that someone with a ton more knowledge will chime in shortly. At least I can give you some things to think about. I know it's not a direct swap, otherwise my old k-20 would have had the tbh400, instead of me having the tbh350 rebuilt. (I had both in the barn.) The 454 will bolt right up to the tbh350, how long it will last is unknown. __________________ '86 C-30 dually, 454/tbh400 '73 K-20 350/350/205 (sold ) I'm kinda like duct tape- no real purpose, but handy to have around.

10-27-2011, 10:10 AM	#4
East End K5 Registered User Join Date: Nov 2004 Location: Long Island NY Posts: 293	Re: Donor questions Ok thx! I do in fact have the TH400 installed in my current truck so I don't have to worry any further with the drive shafts and connecting to the transfer case. The donor was a fire truck and has 60k on the 454...truck was garaged Tranny possibly needs a re-clutch. Engine is tight, no leaks, Rochester 4bl carb needs a deusching. Other than that the cab and clip will be swapped. Posted via Mobile Device __________________ I feel sorry for people who don't drink....because when they wake up in the morning, that's the best they're gonna feel all day long!---Frank Sinatra RIP [B]1972 Chevrolet K5 Blazer RIP 1986 GMC Sierra K3500 1TON, Long Box, V8350 RIP 1980 Chevy Silverado C30 Cab and Chassis, 454 TH400HD. RIP [B] 1995 Chevrolet Tahoe 2D [B]

10-27-2011, 10:08 PM	#5
donut Registered User Join Date: Aug 2009 Location: S.C. Posts: 1,593	Re: Donor questions Sweet!, then I typed all that for nothing, lol Have fun! __________________ '86 C-30 dually, 454/tbh400 '73 K-20 350/350/205 (sold ) I'm kinda like duct tape- no real purpose, but handy to have around.

10-28-2011, 12:08 PM	#6
East End K5 Registered User Join Date: Nov 2004 Location: Long Island NY Posts: 293	Re: Donor questions Ha ha.. Sorry about that! You'll be the last one laughing when I'm covered in grease and soot.... Pictures to follow for entertainment... Posted via Mobile Device __________________ I feel sorry for people who don't drink....because when they wake up in the morning, that's the best they're gonna feel all day long!---Frank Sinatra RIP [B]1972 Chevrolet K5 Blazer RIP 1986 GMC Sierra K3500 1TON, Long Box, V8350 RIP 1980 Chevy Silverado C30 Cab and Chassis, 454 TH400HD. RIP [B] 1995 Chevrolet Tahoe 2D [B]



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