???s for pontiac transplant

[60gmc]

Hi everyone,
I am installing a pontiac 350 and turbo 350 trans in my 60 gmc and I was wandering which trucks would have the correct driveline yolk to fit a turbo 350 trans and my original driveline. the original auto trans and the turbo 350 are the same length, the truck is a short fleetside that had the 305 v6. I am not sure what the original trans is so if anyone has any thoughts on what it might be lets hear it, the idicator pattern on the colum is
N, 1-4, 1-3, 1-2, space, R

thanks,

[kieth]

Just take the original automatic slip yoke and put it on the 350, my 3 spd manual yoke would have worked on a 700r4 but I chose to buy a new one. They should be the same spline count etc. Kieth If it does not fit, find out what does at the driveline shop ..

[Clyde65]

You had the turbo hydromatic I think. But I also think it was possibly a transplant also.

[markeb01]

It sounds like the original transmission is a 4 speed Hydramatic. If so you probably also have the rare and desirable factory transmission crossmember under the tail housing.

http://en.wikipedia.org/wiki/Hydramatic

In my experience the same yoke fits the Powerglide, TH350, manual 3 speed, older model passenger car 4 speeds, and (I think) the SM420 if it has a slip yoke on the back of the transmission (some have a flange). Richmond and Super T10 4 speeds require the larger Turbo 400 yoke. There is a series number on the various yokes, but I don't deal with them enough to remember which is which. I'm not sure what yoke a Hydramatic takes, but it's probably the same as the TH350.

I'd suggest to fit it in place and see if it works.

And welcome to the forum!

[60gmc]

Thanks for the replys, The original trannys tail shaft has fewer splines and is a little larger compaired to the 350 tranny,it would not fit my turbo 400 either. the original tranny has a special adapter for the v6 and the crossmember bolted to the bellhousing. it took a while to figure out how to seperate the two.

[padresag]

[QUOTE=Clyde65;4722695]You had the turbo hydromatic I think. But I also think it was possibly a transplant also.[/QUOTE
the hydramatics used 62 and prior were just plain old hydramatics cast iron case. turbo-hydramatic; the updated version (aluminum housing), known as a 350 or 400
ron

[Str8axle]

4spd Hydramatic should be coarse spline output shaft. TH350 is fine spline. You'll need to change the yoke.
What are your plans for the Hydro?
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[1Bad62Pro/Street]

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[60gmc]

Thanks guys for the info on the trans. I read somewhere that some early gmc trucks came with a pontiac motor in them so i will see if I can find the type of flexplate to mate to the trans. It would be nice to be able to use the original trans if not I will hold on to both motor and trans so they can be put back in if wanted.

[1Bad62Pro/Street]

Originally Posted by 60gmc

Thanks guys for the info on the trans. I read somewhere that some early gmc trucks came with a pontiac motor in them so i will see if I can find the type of flexplate to mate to the trans. It would be nice to be able to use the original trans if not I will hold on to both motor and trans so they can be put back in if wanted.

U.S built GMC's did use a version of the Pontiac V8 from '55 through '59. In 55they used a 287 Pontiac, in '56- a 316, and '57- a 347. In '58 and '59 they used a 336 V8 that was a small bore (3 7/8) vesion of the Pontiac 370 V8. To muddy the waters a bit more, the GMC advertising guys gave the Pontiac engines one extra cube in the brochures in '55 and and '56. Hence the the "Pontiac" 287 was advertised as the "GMC 288" and the Pontiac 316 became the "GMC 317" engine. In these years too, if a 6 cylinder engine was used, the base engine was the 235 inline Chevy. A 261 6 banger that was a stroked Chevy 235 was also offered. In the U.S., GMC dropped the Pontiac engines after '59 and came out will their own, all new 60 degree V6 engine for 1960 - starting with a 305 V6. This engine was expanded over the years and depending on the model and gvw rating, became available in 305, 351, 401 and 478 inch sizes-all of them V6's! They even produced a massive 702 "twin six" V12 version for use in the GMC 'big trucks'.

Canadian built 6 cylinder '55 through '61 GMC's used the 235 and 261 versions of the Chevy 6. '55-59 Canadian built V8 GMC's never used the Pontiac engines. Instead, they came with 265 small block Chev V8's in '55, 56 and '57 (and into early '58) with the 283 Chev V8 becoming optional in '57 and the standard V8 in mid '58 through '67. In '62 the 327 and (1962-'65) 348-409 Chevy engines became extra cost options in various model Canadian GMC's. Beginning in '66, 396 and 366-427 Chevy big blocks were used as optional engines after the phase out of the 348-409 Chevies. Canadian built light duty trucks (under 10,000 GVW) never used the big U.S built V6's- they were simply rebadged Chevies and used the standard Chevy inline 6 or 283-327 small block (or 348-409 or 366-427 V8's in the heavy trucks), although the 401, 478 V6 and 702 V12 could be "special ordered "in the big (over 10,000 lb GVW) GMC trucks in Canada.

http://en.wikipedia.org/wiki/List_of_GM_engines

http://history.gmheritagecenter.com/..._Truck_History