which transmission do i have? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

79SWBchevy · 12-07-2009, 04:46 PM

i have a 79 swb with the 250 I6. what transmission could i possibly/most likely have?

will it bolt up to a 350 or is the bell housing different?

thanks alot

79gmcc15 · 12-07-2009, 05:58 PM

is it manual or auto? if its manual I would guess its a 3 speed on the tree, if its a auto then I would guess its a TH350.

brothers69c-10 · 12-07-2009, 06:18 PM

A guy once put it this way to me when i asked if the th400 was buying from him would bolt up to the 454 i was also buying from him.

"If you wanted to put the big block in a vega and use the stock transmission in the vega it will bolt up, i don't know why you would do that, but it will work"

I could be wrong on this and so cold the gentleman i quoted, but i am guessing not. The only problem i can foresee is clutch linkage. Also if its a three on the tree its probably an old saginaw or if its a 4 on the floor its probably an sm465 i believe.

78-5.3 · 12-07-2009, 06:47 PM

Quote:

Originally Posted by 79SWBchevy

i have a 79 swb with the 250 I6. what transmission could i possibly/most likely have?

will it bolt up to a 350 or is the bell housing different?

thanks alot

no matter what it is the(standard or auto) belhousing will boltup

68 TT · 12-07-2009, 06:55 PM

Quote:

Originally Posted by 78-5.3

no matter what it is the(standard or auto) belhousing will boltup

Are the inline-6 flywheels the same as a sbc / bbc? I've never owned one so I don't know if they were unique but I don't remember any application guides listing the six with sbc / bbc flywheels & flexplates.

ont_guy_38 · 12-07-2009, 07:11 PM

yes a sbc/bbc will bolt up to that tranny

cableguy0 · 12-07-2009, 09:01 PM

the only engine used in a rwd application that had a different bellhousing was the 2.8 v6 in trucks. its a GM just about everything is interchangeable

68 TT · 12-08-2009, 12:19 PM

Quote:

Originally Posted by cableguy0

the only engine used in a rwd application that had a different bellhousing was the 2.8 v6 in trucks. its a GM just about everything is interchangeable

Newer stuff yes, 50's, 60's, 70's & early 80's stuff no. Chevy V-8's and 90 degree V-6 share bolt patterns. Buick, Olds & Pontiac V-8's use a different bolt pattern, Caddy another.

A Caddy 500 inch motor is an incredible truck engine. A little cheaper to build including core cost than a big block Chevy.

mhicks · 12-08-2009, 02:14 PM

Good link for info on transmissions
http://www.novak-adapt.com/knowledge...on_gateway.htm

dbmx66 · 12-08-2009, 02:34 PM

post a picture of what the trans pan looks like.

79SWBchevy · 12-08-2009, 11:41 PM

thanks for all the responses.

it is an automatic.

as far as the pictures, it may take a while for me to get pictures up, maybe about 3 weeks.

thanks alot guys

brothers69c-10 · 12-08-2009, 11:59 PM

Since its an automatic its going to have either a th 350 or th 400. I'm putting money on the th350 as i've never heard of a th400 behind an inline 6 unless somebody has swapped it out some time between it came from the factory and when you got the truck. If its a th 350 the pan will look like a square with one corner a little different. If its a th400 the pan will look like a funny shaped texas.

68 TT · 12-09-2009, 12:16 PM

Quote:

Originally Posted by brothers69c-10

Since its an automatic its going to have either a th 350 or th 400. I'm putting money on the th350 as i've never heard of a th400 behind an inline 6 unless somebody has swapped it out some time between it came from the factory and when you got the truck. If its a th 350 the pan will look like a square with one corner a little different. If its a th400 the pan will look like a funny shaped texas.

They have done some strange stuff trans wise so I wouldn't completely rule it out but you are probably right. A T-350 is the most likely candidate.

I actually found a factory 4.3 V-6 92 vintage full size truck with a 4L80E trans in it so anything is possible.

12-07-2009, 04:46 PM	#1
79SWBchevy Registered User Join Date: Nov 2009 Location: Hurley, MS Posts: 84	which transmission do i have? i have a 79 swb with the 250 I6. what transmission could i possibly/most likely have? will it bolt up to a 350 or is the bell housing different? thanks alot

12-07-2009, 05:58 PM	#2
79gmcc15 Gettin It One Pice At A Time Join Date: Oct 2004 Location: everett, washington Posts: 2,688	Re: which transmission do i have? is it manual or auto? if its manual I would guess its a 3 speed on the tree, if its a auto then I would guess its a TH350. __________________ RIP ELJAY Work In Progress 1979 GMC C1500 Trailering Special. Getting the truck done, one piece at a time. “You can tell a lot about a fellow’s character by his way of eating jellybeans.”Ronald Reagan “I don’t know the key to success but I know the key to failure is trying to please everybody.” Bill Cosby

12-07-2009, 06:18 PM	#3
brothers69c-10 Suburban Hick Join Date: Aug 2008 Location: Altoona, IA Posts: 810	Re: which transmission do i have? A guy once put it this way to me when i asked if the th400 was buying from him would bolt up to the 454 i was also buying from him. "If you wanted to put the big block in a vega and use the stock transmission in the vega it will bolt up, i don't know why you would do that, but it will work" I could be wrong on this and so cold the gentleman i quoted, but i am guessing not. The only problem i can foresee is clutch linkage. Also if its a three on the tree its probably an old saginaw or if its a 4 on the floor its probably an sm465 i believe. __________________ Mathew 1947 Chevy 3600 1951 GMC 100 1969 Chevy C-10 396/500hp TH400 lowered 4" 1968 Imapla Custom 396/325hp TH400 "Grandmas Car" 1976 Crew Cab 4x4 diesel http://67-72chevytrucks.com/vboard/s...d.php?t=488505 1978 Chevy K-10 454 1983 S10 4x4 "Bumblb" (Grandpa's truck) 1993 Chevy S10 V8 conversion 1990 Ford Probe Gt 1992 Dodge W-150 "Old Man's Truck" 1992 Pontiac Grand Prix SE 1992 Mercury Grand Marquis-Mercruiser 2000 Ford F150 (Currently my mother drives this) 1946 Farmall H with Stan Hoist loader 1965 John Deere 110 1961 Wheel Horse " Rat Tractor"

12-07-2009, 07:11 PM	#6
ont_guy_38 Registered User Join Date: Jul 2007 Location: Ontario Canada Posts: 1,006	Re: which transmission do i have? yes a sbc/bbc will bolt up to that tranny

12-07-2009, 09:01 PM	#7
cableguy0 Senior Member Join Date: Apr 2000 Location: Delta,Pa Posts: 14,950	Re: which transmission do i have? the only engine used in a rwd application that had a different bellhousing was the 2.8 v6 in trucks. its a GM just about everything is interchangeable __________________ Owner of North Point Car Care in Dundalk Md. We specialize in custom exhaust on both modern and classic vehicles. We are a full service auto shop from classics to modern vehicles. Feel free to contact me with questions. I will give a 10% discount to any board member.

12-08-2009, 02:14 PM	#9
mhicks Registered User Join Date: Jan 2004 Location: Weatherford,Tx Posts: 747	Re: which transmission do i have? Good link for info on transmissions http://www.novak-adapt.com/knowledge...on_gateway.htm

12-08-2009, 02:34 PM	#10
dbmx66 Registered User Join Date: Aug 2009 Location: PA Posts: 883	Re: which transmission do i have? post a picture of what the trans pan looks like.

12-08-2009, 11:41 PM	#11
79SWBchevy Registered User Join Date: Nov 2009 Location: Hurley, MS Posts: 84	Re: which transmission do i have? thanks for all the responses. it is an automatic. as far as the pictures, it may take a while for me to get pictures up, maybe about 3 weeks. thanks alot guys

12-08-2009, 11:59 PM	#12
brothers69c-10 Suburban Hick Join Date: Aug 2008 Location: Altoona, IA Posts: 810	Re: which transmission do i have? Since its an automatic its going to have either a th 350 or th 400. I'm putting money on the th350 as i've never heard of a th400 behind an inline 6 unless somebody has swapped it out some time between it came from the factory and when you got the truck. If its a th 350 the pan will look like a square with one corner a little different. If its a th400 the pan will look like a funny shaped texas. Attached Images __________________ Mathew 1947 Chevy 3600 1951 GMC 100 1969 Chevy C-10 396/500hp TH400 lowered 4" 1968 Imapla Custom 396/325hp TH400 "Grandmas Car" 1976 Crew Cab 4x4 diesel http://67-72chevytrucks.com/vboard/s...d.php?t=488505 1978 Chevy K-10 454 1983 S10 4x4 "Bumblb" (Grandpa's truck) 1993 Chevy S10 V8 conversion 1990 Ford Probe Gt 1992 Dodge W-150 "Old Man's Truck" 1992 Pontiac Grand Prix SE 1992 Mercury Grand Marquis-Mercruiser 2000 Ford F150 (Currently my mother drives this) 1946 Farmall H with Stan Hoist loader 1965 John Deere 110 1961 Wheel Horse " Rat Tractor"



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