Equipping a G-Body with a manual trans

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Bonnewagon

Lost in the Labyrinth
Supporting Member
Sep 18, 2009
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Thank's GP but the dash would be sh*t without the tach you sent me. Gotta give credit where credit is due. :D Doober, see how the shifter handle is centered in the console? That's because the shifter is #3914340 for a 67'-69' Camaro/Firebird. Look back in the charts you posted and in the shifter section you will see how it has a nice 3" offset. The stock A/G body shifter sits more to the left and that's why the factory floor plate is tilted that way. I used the stock one like you when I had no console, but switched to the 68' one to get it more to the center.
 
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86Cutlass383SR

G-Body Guru
Apr 1, 2009
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Sesser, IL
I'll post up my experiences and methods I have in my T56 swap.

I originally started out with a T5 swap into an 84 Cutlass with a TPI fuel injected 383 SBC. I bought a T5 setup from a guy who had all this in his Monte SS so all the "engineering" was done for me, not by me. I got a set of f-body pedals (mid to late 80's) which had the old g-body firewall mounting tabs welded to the f-body pedals. The mounting holes slide over the studs from the back of the brak booster and are farther apart on the g-body booster than the f-body booster.

The crossmember I used was from the stock 3 speed automatic V6 Buick transmission. I used a piece of steel 1/2" thick and about 2" long with 2 holes. Bolted one end to the crossmember and the other end to the trans. Kinda Jerry-rigged but I *waz gonna* buy/have made a correct crossmember.

I was originally using the f-body hydraulics with the T5. As was stated earlier and in the picture, I removed the wiring and hose for the cruise control and mounted the master cylinder thru that hole. I then used the master as a template to drill the mounting holes. The slave then attaches to the f-body clutch pedal.

I was using a bellhousing from an 85 - 92 Camaro for the hyd equipped cars. I used, again, the stock Camaro T5 slave cylinder. Basically, from the clutch/brake pedal assembly to the hydraulics, bellhousing, 84 or 85 Camaro flywheel (153 tooth 2 pc RMS), clutch/pressure plate (10.4") and World Class T5 was all from the Camaro. Now for my evaluation. Pros: All parts readily available from dealer or parts supply houses (Autozone, O'Reilly's, Napa, etc.). Cons: Never really liked the hydraulic actuation though that could be personal preferance. Seemed like the clutch wanted to slip easier than normal due to possibly not completely releasing the clutch. Tried new, prebled master/slave assembly. Same results. Had no adjustability. Could have maybe shimmed the slave back from the bell farther with the risk of not enough slave rod travel.

I used the Hedman shorty headers, yes, also for a Camaro. #68470 clears the hydraulics nicely and fits the g-body frame.

It was at this time I swapped to the Aftermarket T56. I bought it from Liberty. It's now Liberty Gears. http://www.libertysgears.com/ttc.htm
With shipping to Southern Illinois it was a few dollars shy of $2000 back in 2003 - 2004. UPS guy delivered it in 2 boxes to stay under the 150# weight limit with the included adapter plate. Comes with the same adapter plate pictured on page 1. Some adapter plates are drilled for both the regular Muncie style pattern and the canted T5. Others are only drilled for the T5 pattern. Mine is drilled for both.
***NOTE: The pictured extended pilot bushing below the adapter plate is only used with the LS1 transmission. My Aftermarket T56 (#1386-000-011) uses a regular pilot bushing.
The Aftermarket T56 was developed to replace the weaker T5. The T56 is longer than the T5 (approx 2.5" I believe) requiring a shorter driveshaft. It uses a conventional T5 speedo output meaning either the stock mechanical speedo cable or the elec VSS for the Camaro's elec speedo. The adapter plate has a throwout bearing retainer so a stock T5 type clutch/pressure plate (or aftermarket replacement) can be used. Aftermarket T56 comes with a shifter mechinism but no handle. Since it's setup to take a Mustang Cobra shifter, I bought an aftermarket shifter.

While doing my swap and not being real happy with my hydraulic setup, I changed over to the mechanical linkage. Having used mechanical linkage in numerous 69 Camaro's, I liked the feel much better and it was also adjustable. I couldn't find a stock g-body bellhousing or a bell from an 82 - 83 Camaro (which is also mechanical and 2 year only), I bought a new Lakewood bell for the mechanical Camaro (Lakewood #15015) and the recommended Lakewood clutch fork. Since both the bell and my adapter plate are drilled for either bolt pattern, I used both sets of holes to bolt the plate to the bellhousing. Countersunk bolts are needed. This transmission is heavy (almost 150# with plate) and the Lakewood is a stout piece so I figured the extra bolts only reduced any possible stress. The transmission then bolts to the plate after it is bolted to the bell.

I used the mentioned Speed Direct linkage rods (NICE product and very reasonably priced at $65.10). After using these linkage rods, please replace your stock rods! They ARE that nice. I also bought the g-body frame bracket and the z-bar. Most (if not ALL) frames have the needed 3 holes in the frame for the bracket in the fenderwell area behind the front suspension. Simply use 3 self-tapping bolts and bolt the bracket to the frame. All conventional SBC/BBC blocks have the needed hole for the ball for the z-bar. The other end has another ball which bolts on the frame bracket. I used the same Camaro pedals that I had previously used with the hydraulic setup.

I reused the same flywheel as the T5 setup had and dropped in a new clutch/pp when I swapped from T5 to T56. T5 I used a Centerforce and with the T56 I went with a Spec Stage 3. I bought a crossmember very simular to the Crossmembers.com RCGT56.

Everything bolted together just like stock as well they should. The mech Camaro bell works flawlessly with the g-body linkage. Partially cured my clutch slippage problem. Held good in 1st - 4th gears with my Spec Stage 3 clutch/pp in a stock style 10.4" size. Still slipped somewhat in 5th & 6th gears if I stood on it really hard. Maybe my fuel injected 383 was a bit much for a 10.4'' clutch...?

My 84 Cutlass suffered from terminal cancer and I found an 86 Cutlass in better shape and the 383 needed a rebuild, the 84 got stripped and scrapped. All good parts are being installed on the 86. The 383 should be done in a week or so. I went with a new 168 tooth flywheel that can use an 11" clutch since my Lakewood bell can handle that size. A new Centerforce clutch/pp will go back in.

Unfortunately, since my car is sitting outside for now, progress has been painfully slow (or non-existant!!!) the last few months. Hopefully I can get it moved into the garage and get things back on a progressive trail.

I think that pretty well covers my trials & tribulations of my manual journey. It sure makes a g-body so much more fun being a manual and totally unique compared to most others you see.
 
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Doober

Royal Smart Person
Apr 8, 2007
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Something else I found today. I've been looking for this for quite sometime, because I'm hoping to stick with mechanical linkage in the 'Bu if I can, whenever I go to an LS motor. It's a bracket to mount a ballstud in the factory location on a Gen I SBC.
http://sdparts.com/details/scoggin-dick ... enter/sdcb
SDCB_full.jpg


If I can run an LS motor with mechanical linkage and headers in a G-Body I'll be a happy camper :D
 

86Cutlass383SR

G-Body Guru
Apr 1, 2009
720
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Sesser, IL
Doober - I don't know what type of manual transmission you plan on running with an LSx, but Lakewood makes a mechanical bellhousing for an LSx engine using a Muncie, Saginaw, or Borg Warner transmission.

http://www.summitracing.com/parts/LAK-1 ... mage=large

With the above bracket and this bellhousing, all your dreams should come true.
 

Doober

Royal Smart Person
Apr 8, 2007
1,253
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Swartz Creek, MI/Tucson, AZ
Yeah, I don't think I'd have much choice but to go aftermarket on the bellhousing, from my understanding the flywheel is 168 tooth-size so a stock G-Body bellhousing won't work. Either that or find an appropriate F-Body or Corvette bellhousing and fork.
 

Chillin014

Master Mechanic
Nov 9, 2007
422
0
0
houston/richmond tx
First of all thanks to doober (and everyone else providing information)

My t5 just bit the dust so I think I'm going to upgrade to a t56. It sounds like with the bellhousing adapter I can pretty much retain my current hydraulic system,flywheel,starter, bellhousing, and clutch. So I should only really need to have the driveshaft shortened (again :? ), a new crossmember, and the bellhousing adapter and I should be good to go, right?
 

86Cutlass383SR

G-Body Guru
Apr 1, 2009
720
6
0
Sesser, IL
Pretty much. Depending on which T56 use use, the LT1 trans has differant input shaft dimentions than an LS1 trans. Make sure all your parts are compatible. If you buy a new Aftermarket T56 then the adapter plate comes with it. If you have a cable driven speedo, then you will have some adapting to do there as well. Most T56's have electric senders (VSS singnal generators) fo the electric speedos. The aftermarket T56 uses the T5 setup so you can use your old T5 VSS or cable output.
 

Chillin014

Master Mechanic
Nov 9, 2007
422
0
0
houston/richmond tx
I definitely dont have 2 grand for an aftermarket unit. As far as the input shafts being different, are the spline counts different? Or are you just referring to the input shaft bearing?

The speedo doesnt concern me, if its VSS I will just buy a new speedometer to accommodate it.
 

pontiacgp

blank
Mar 31, 2006
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Kitchener, Ontario
you can get your T5 rebuilt with stronger gears for less than you'd pay a used T56.....plus the T5 is about 75 pounds lighter and unless you have a 3:73 or higher you'd probably never use the T56 second overdrive gear. One of my T5 transmissions has a .68 overdrive gear and with a 3:08 rear the engine is only reving 2000 at 75 mph....the second overdrive gear in the T56 is .50
 
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joey_schel

Apprentice
Feb 11, 2009
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Stratford, Ontario
I dont know if t5 is that much lighter, t56 is 130 or so, t5 i believe is about 80? Love that 0.5 overdrive personally, but pontiac is right; with high gears (3.23, 2.73, etc) your going to be bogged down and likely never use that gear. It actually made my mileage go down when i had 2.73 gears b/c the motor was chugging along so hard

Has anyone with a transmission that has a VSS electronic speedo found a way to make the factory gauge work? Maybe one of those adapter boxes? I really dont want to switch to an autometer or something; a stock gauge would look so much better in the cluster in my opinion
 
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