86 c10 Driveline is too short

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

Billys44s

Junior Member
Joined
Jul 5, 2021
Posts
11
Reaction score
1
Location
Mcalester Oklahoma
First Name
Billy
Truck Year
1986
Truck Model
High sierra
Engine Size
400 Sbc
Hey guys

I recently bought a th350 from oreillys for it to turn out to be Th350c transmission.
My Square originally had a regular th350 short tail in it then it was swapped a few years back to a used 700r4 and last year the 700r4 lost 3-4 so I went ahead and bought a brand new trans to put a end to the headache and when I got home I realized this th350 was different from the original the truck had in it.

long story short it turn out to be the th350c and I went ahead and used the yoke out of the 700r4 and after getting everything installed, the drive as barely off maybe about an inch and I’m stumped on what I could do to make it work.

I have the original yoke from the th350 that came factory in the truck but idk if it would fit or give me the length I need to make the drive line work.

any help will be appreciated
 

Rickf

Full Access Member
Joined
Jul 29, 2017
Posts
571
Reaction score
713
Location
Grafton NH
First Name
Rick
Truck Year
1974, 1954 & a 1937
Truck Model
K20
Engine Size
350
What about having a driveshaft made up?
 

Billys44s

Junior Member
Joined
Jul 5, 2021
Posts
11
Reaction score
1
Location
Mcalester Oklahoma
First Name
Billy
Truck Year
1986
Truck Model
High sierra
Engine Size
400 Sbc
What about having a driveshaft made up?
I’ve thought about having one made but I haven’t got a quote on one, I thought since it had a th350 originally that the drive shaft should go in without a problem or is there a difference in length between th350 and the th350c driveline?
 

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,948
Reaction score
25,339
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
I wanna say yours probly had the intermediate shaft length (6 inch) originally. Ive been through 4 th350s in my c10 and all are 6" tails.
 

Billys44s

Junior Member
Joined
Jul 5, 2021
Posts
11
Reaction score
1
Location
Mcalester Oklahoma
First Name
Billy
Truck Year
1986
Truck Model
High sierra
Engine Size
400 Sbc
I wanna say yours probly had the intermediate shaft length (6 inch) originally. Ive been through 4 th350s in my c10 and all are 6" tails.


I would say your correct. I never really measured the original but I knew the tail shaft looks identical to the one down below, I think the 700r4 I had was a 6 inch tail too but it was a tight fit to mate the driveline to the rearend. This Th350c is the old ball because is just barely off from fitting and I have no idea why,if it supposed to be the correct trans for the truck why the driveline is off it puzzle me because I’d figure a 6 inch would be a direct swap in Since that what it had originally

You must be registered for see images attach
 

C10MixMaster

Full Access Member
Joined
Dec 6, 2016
Posts
756
Reaction score
1,424
Location
Kingman AZ
First Name
Ben
Truck Year
1977
Truck Model
C10 BIG10
Engine Size
ZZ4 350
You have 2 different things going on . First the difference between a th350 and a th350c is the C has a lock up torque converter. C has nothing to do with overall length. TH350th/350C transmissions came with 6"9"12" tail housing depending on application. my experience is trucks got the 9" and vans got a 12" . A turbo 350/350C with a 9" tail housing is about 30 5/8" and a 700r4 is about 30" (unless its a corvette model) .

You must be registered for see images attach
 

78C10BigTen

Full Access Member
Joined
Apr 12, 2017
Posts
15,948
Reaction score
25,339
Location
pennsylvannia
First Name
Ted
Truck Year
1978
Truck Model
C10 BIG TEN
Engine Size
350
You have 2 different things going on . First the difference between a th350 and a th350c is the C has a lock up torque converter. C has nothing to do with overall length. TH350th/350C transmissions came with 6"9"12" tail housing depending on application. my experience is trucks got the 9" and vans got a 12" . A turbo 350/350C with a 9" tail housing is about 30 5/8" and a 700r4 is about 30" (unless its a corvette model) .

You must be registered for see images attach
You brought up a point here, i miss spoke. My th350s were 9" tails
 

59840Surfer

Full Access Member
Joined
Oct 8, 2020
Posts
206
Reaction score
335
Location
Montana
First Name
Joe
Truck Year
1986
Truck Model
K5
Engine Size
350 Stroker to 383 with a 400 crank, Crane Cam, Q-Jet, single 3.5" exhaust..
" (ibid) ....... so I went ahead and bought a brand new trans to put a end to the headache <snip> "
Where did you buy as "brand new trans(mission)"?

Brand new transmissions are usually wrapped inside a brand new vehicle and I have yet to find any brand new ones (except for the ZF-Fords*) in all my 55+ years as a mechanic that were any more then Rebuilt, Reman'd or Used.

* I ain't going there.
 

Forum statistics

Threads
44,163
Posts
950,682
Members
36,276
Latest member
2manysquares2care
Top