Swap Saginaw 4 speed to World Class T5

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Swap Saginaw 4 speed to World Class T5

Postby Vega2008 » Sat Jan 27, 2018 5:53 am

Okay, first off I admit to being totally clueless when it comes to transmission swaps for the 1975 Chevy Vega Hatchback.

I am going to ask some questions here that maybe have been asked before, but I need to ask these questions before I spent a boat load of money to find out I bought the wrong parts...I don't want to go there, I can't afford to do this wrong.

I need help from somebody that has actually done this before, and the correct part numbers would be extremely helpful.

What I have:
I have a 1975 Chevy Vega Hatchback, it has the original 4 speed Saginaw transmission, and transmission cross member. It also has the stock driveline and stock rear end. These currently work ok, I just want better cruising speed on the highway with lower RPM's.

My 1975 Chevy Vega Hatchback had no engine when I bought it, but it had Buick V6 motor mounts and a BOP bell housing that has a cable operated clutch set up to the stock clutch pedal assembly. I am fairly certain that the stock tranny and tranny mounts were never altered or moved. I did not install the motor mounts they were already there for the Buick V6. I bought a running 1979 Buick Even Fire Buick V6 from a wrecking yard, I tore it completely apart and took it to a machinist to have the block completely gone through with new crank, new connecting rods, new pistons, new camshaft, bearings, rings. Heads were completely redone too. New flywheel for the Even fire since I didn't have one originally. The block was balanced internally, and also balanced by the flywheel. Instead of the typical 105 to 110 HP...I had it built to put out 275HP. Using an Edelbrock Performer manifold with ABF400 carb.
This motor was built in the late eighties, and the car was a daily driver for 7 to 8 years. I still have low miles on motor, still runs great so I am going to keep it, and run it until it dies then either swap it for a V8 or find another V6 for it. It gets around 26 to 28 MPG with the current setup, which was why I built a V6 Vega instead of a V8 Vega. This is not going to be a race car, but a daily driver type of car.

I want to swap out the Saginaw 4 speed for a T5 Transmission (World Class if recommended...and NOT a T50 tranny) behind my cable operated BOP Bellhousing if I can do that.

I need to know if a Camaro T5 bolt pattern tranny will bolt up to my BOP bell housing for an 1979 EVEN FIRE Buick V6 (This is Not a 3800 Buick V6) and if this is the best solution or not.

If the Camaro T5 tail shaft is too long for the shifter hole can the Ford T5 tail shaft be installed on the GM Transmission housing to put the shifter in the stock shifter hole, or closer to the stock shifter hole?
Will an S10 tail shaft be a better length to match my stock shifter hole?

What are my best options for a T5 tranny, so that I can get a T5 in there and have the T5 shifter line up the best with my stock 4 speed shifter hole?

If I swap to a Ford T5 Tranny, is there a specific adapter I can use to mount the tranny to my BOP tranny pattern (Same as Saginaw tranny pattern)?

I really need some good advice on this from somebody that knows what they are talking about, and has done this swap before if possible.

I do not have a Chevy Bell Housing, it is a BOP bell housing that mates to my stock Saginaw 4 speed.

Will you need a serial number from my BOP bell housing to answer any of these questions?

And if I am successful in getting the correct tranny / clutch / pressure plate too I assume...can I use a hydraulic setup instead of the cable for the clutch?

Probably also ought to mention that I know a shorter drive shaft may have to be made, a different yoke from the tranny output shaft, and a different tranny mount.

Part numbers would be awesome if you have specifics about what worked.

Thanks for any help you can provide me to save me time and money.

If you want to shoot me an email and or send me pictures and information I can be reach here if you want to do that:
Mike Steinert - VEGA2008 - michael.steinert60@gmail.com, or steinerts@mindspring.com, or michael.steinert@libertymutual.com
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Re: Swap Saginaw 4 speed to World Class T5

Postby TimMcCabe » Sat Jan 27, 2018 10:21 am

Hi Mike,

I ran a Z28 T5 in my '72 Vega for years before swapping it to a T56.
If you want to run a WC T5, you need to find a 91 Camaro, as it was the only WC that still has a speedo drive. From 92 on, the speedo was electronic.
The tailshaft from a 2wd S10 T5 will fit the Camaro trans and put the shifter very close to the stock location.
You may also have to grind a little bit off the front of the trans housing to clear the clutch pivot adjustment nut.
I was running the Camaro bellhousing with a hydraulic clutch, so I can't speak directly to that.
The Ford T5 has the wrong bolt pattern for your bellhousing and I think the input shaft is longer as well. There might be adapters to bolt it up, but they won't be cheap.
Do a search in the forum for T5 swap, there is alot of info here.. You can also google S10 tail housing on Camaro T5 and see some photos of the conversion.

1972 TPI Vega T56 6 speed

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Re: Swap Saginaw 4 speed to World Class T5

Postby Monza Harry » Sat Jan 27, 2018 9:34 pm

Tim and Fred are the only two I remember doing the T-5 swap, both however are SBC powered and I just don't know enough [anything] about the BOP pattern interchange to be any help there. So you have heard from Tim, here is Fred's "User Profile" : memberlist.php?mode=viewprofile&u=757 Search his posts and follow along his build up, I recall Fred giving "much" info along the way, between them you should have most everything you need. Keep us posted as well. Harry
I'm not a hoarder I'm a preservationist 78 Monza Spyder (Soon To Be 2+2 with Spoilers)
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Re: Swap Saginaw 4 speed to World Class T5

Postby cammerjeff » Sun Jan 28, 2018 1:41 am

Its not apples to apples, but I put a WC T-5 behind my Pontiac OHC-6 in my 1969 Firebird. I used a Trans from a 86 Trans Am, I was able to use the standard Pontiac V8 clutch, I went with a centerforce duel friction clutch and was able to use the standard Pontiac V8 throw out bearing, and all the stock OHC-6 clutch linkage. The issue to with the F-body T-5 was the 18 degree offset to the passengerside that the F-body trans mounts (82-92) the 93-2002 F-Body T-5's use the Ford case and require an adaptor plate to mount to the T-5 to a BOP Bellhousing.

On my 77 Astre 215 Buick Build I had wilcap make a one off tilted adaptor plate to mount the 97 Firebird (ford bolt pattern with the 18 degree tilt) straight up on m Buick 215. I used a modified Buick 215 bellhousing to work with the Vega style cable operated clutch. Unfortunatly I haven't completed the install in my Astre. But the install in my Firebird has worked well for 15+ years & over 10,000 miles. Other than the tilt of the shifter towards the passenger seat, but that is only excessive in 5th & reverse.
Jeff R

78 Sunbird Safari Wagon, 3.8 N/A, 1971 Catalina Freeway Enforcer
77 Astre Formula, some day soon powered by a 215 Buick V-8
1973 4-speed Lemans Safari STOCK!!!!! 1978 Catalina Safari
1969 Firebird Sprint 301 ci OHC6, T-5, 4.10 12 bolt posi
2006 Mallet Solstice, 6.0 LS2, 6-speed manual
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Re: Swap Saginaw 4 speed to World Class T5

Postby monzaaddict » Sun Jan 28, 2018 5:46 am

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Re: Swap Saginaw 4 speed to World Class T5

Postby jim327monza » Sun Jan 28, 2018 12:07 pm

Their are after market t-5 that have the same bell housing to transmission bolt housing as the Saginaw pattern . a lot of the early gm t-5 use this same bolt pattern. the camaro t-5 is rolled (18 degree to the driver side). using any bell housing other than the Camaro will put the sifter straight up and roll the mounting pad. Input shaft length will be different between the v-8 and v-6 . I chose to have a 93 Camaro W/C t-5 rebuilt with Z-spec gears , bolted to a stock Monza bell housing that put the shiftier in the up right position. Shiftier cleared the stock Monza opening by 3/8 to 1/2 inch at rear. Using 1 by 2 rectangle tubing to lower the stock cross member and 1x1 angle to create an angled adapter between the mount pad and the foot on the transmission. Everything is bolted together and required no modification of the cross member or frame . I am using stock pull cable set up with plans to convert to hydraulic . Hope this answers some of your questions.
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Re: Swap Saginaw 4 speed to World Class T5

Postby OldsStarfire » Fri Mar 16, 2018 12:32 pm

I did a nwc T5 behind my Buick V6: viewtopic.php?f=19&t=852
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