Master cylinder for a T56?

[90'rado]

I'm also running a T56 in an OBS ('90 RCSB) and I'm using the regular truck master and it works fine. My T56 is LTx based so I'm running an Fbody Slave cylinder. I used the stock GM truck hydraulic clutch line and it worked fine, although I had to really change the bends to work with the T56. I'd go for a braided custom line if I did it again, just to save a little bit of time maybe.

My buddy put together this writeup on swapping out a 4L60 for a T56 *dialup warning*
http://www.gmt400.com/forum/showthre...ialup-warning*

pnhigg, have you ever had any problems with your hydraulic TOB?? Where can I find one for cheap??? I'm planning on convertiny my LTx T56 to an LSx T56 once I get the money to buy an LQ4 and do that swap. Also, the LQ4 will work with the LS T56 won't it???? I remember reading something about a different crankshaft flange length or something on the LQ4. I bet the 5.3 and T56 is a great combo with the 4.56 gears. I'm working on swapping out the 10 bolt-3.08 axle under my truck currently for a 14 bolt-4.88 w/ truetrac.

[gl18rider]

Thanks guys. I was misinformed by NAPA on the bore size of the truck master. They reported 7.75mm and the Fbody at .75 in. Turns out on further investigation the truck is actually 11/16. So, it has just a little more stroke than the Fbody and 1/16" smaller bore. It'll be interesting with the internal slave from the LS1's T56, but I'm feeling more confident about it. Thanks again for the feedback. I'm surprised I'm not seeing more LS1-T56-based trucks.

How much futher back is the T56 shifter from stock in your trucks (my truck was 305/5spd)?
-gl18rider

[pnhigg]

gl18rider:
I thought the truck master had plenty of volume as I had checked when I did my conversion, but couldn't remember the measuments off hand, and was afraid to say. Glad you got the correct numbers.
I have a 5.3/T56 in mine and I used the transdapt plates to move the motor mounts so the sbc mounts would work. That moved the engine foward a little (I had a 4.3/5 speed originally). With that set up, the T56 shifter comes out right in front of the seat. If you put buckets in and build or buy a console, you can use that shifter location. If you keep the bench it will be pretty difficult. I bought and installed a shifter relocator kit from Keisler Automotive in Knoxville. I moves the shifter to the front hole in the T56 which allowed me to use the original hole in the floorboard of the truck. I had to add a hurst stick, knob, and boot, but I really like it. My truck looks virtually stock inside, which was what I was going for.
I will try to get some pictures posted of my interior fwiw

90'rado
I am pretty sure, but check me on this. The LT T56 has a longer input shaft, and a different bell housing. The internals, short of the input shaft are the same otherwise.
The lsx T56 will bolt up to an LQ4 from all I have understood.

The 5.3/T56 is a blast to drive. I have a mild cam 222/224 and some good tuning, so for a really mild set up the truck makes good power and is fun to drive. The 4.56 gears are awesome. The 4.56 give really good grunt in the low gears to get a truck moving, then with the double overdrive you can cruise at 70mph at 2000rpm.

interior 2.jpg

interior 1.jpg

If the pictures don't show, let me know and I can email them, if you'd like.

[gl18rider]

Thanks for the pics.
That's nice! That looks very good. I wondered about the relocation kit. Is it pricey?
With 4.56 you can run at 70 mph and 2k rpm? That's great. I was considering 3.73, now might consider 4.11.

[pnhigg]

the kit wasn't cheap but I don't remember the cost.
http://www.keislerauto.com/gm/gm-bar...page_tabs.html

Following is the link. If it doesn't work you can find it in the gm section of their website, then click on the 6 speed section, and scroll near the bottom. Their customer service guys are very helpful regarding swaps and such, so don't hesitate to call them if you think you might be interested in the shifter relocator.

On the gears...everyone has different preferences. With my little engine, and the mild cam, it likes to spin a little more than stock, so it actually doesn't like lugging under 1500rpm or so, so the 4.56 keep the engine spinning a little faster. Even so, 70 mph at 2000 rpm is not bad in my mind (I have 295/45 R18s on the back of the truck). I don't want to suggest anything too strongly, but I would not go with any gear higher than 4.10. I think you are going to want the lower ratio to get the truck moving.

FWIW I started with the factory 3.08 when I first put the engine transmission in. After a few months of shopping I found a good deal on an Eaton LSD with 4.56 gears and bought it. I could tell almost as much different (seat of the pants) when I changed the gears as when I changed the engine and transmission.

[90'rado]

gl18rider:
I thought the truck master had plenty of volume as I had checked when I did my conversion, but couldn't remember the measuments off hand, and was afraid to say. Glad you got the correct numbers.
I have a 5.3/T56 in mine and I used the transdapt plates to move the motor mounts so the sbc mounts would work. That moved the engine foward a little (I had a 4.3/5 speed originally). With that set up, the T56 shifter comes out right in front of the seat. If you put buckets in and build or buy a console, you can use that shifter location. If you keep the bench it will be pretty difficult. I bought and installed a shifter relocator kit from Keisler Automotive in Knoxville. I moves the shifter to the front hole in the T56 which allowed me to use the original hole in the floorboard of the truck. I had to add a hurst stick, knob, and boot, but I really like it. My truck looks virtually stock inside, which was what I was going for.
I will try to get some pictures posted of my interior fwiw

90'rado
I am pretty sure, but check me on this. The LT T56 has a longer input shaft, and a different bell housing. The internals, short of the input shaft are the same otherwise.
The lsx T56 will bolt up to an LQ4 from all I have understood.

The 5.3/T56 is a blast to drive. I have a mild cam 222/224 and some good tuning, so for a really mild set up the truck makes good power and is fun to drive. The 4.56 gears are awesome. The 4.56 give really good grunt in the low gears to get a truck moving, then with the double overdrive you can cruise at 70mph at 2000rpm.

I'm running buckets now, although I was able to use a bench seat along with the stock shifter position by making a custom shifter handle to clear the bench. My camera is currently lost at the moment, but if I ever find it, I'll upload some pics of where my shifter comes up for comparison. Here is a pic of the first shifter I built to run the stock location with the bench. I have since replaced it for a short throw PRO 5.0 shifter.

Right, that's how I understand it as well, the LSx and LTx T56's are internally identicaly, everything from the frontplate/midplate forward is different between the two (frontplate, input shaft, bellhousing, clutch assy.)

Thanks for the pics.
That's nice! That looks very good. I wondered about the relocation kit. Is it pricey?
With 4.56 you can run at 70 mph and 2k rpm? That's great. I was considering 3.73, now might consider 4.11.

I've talked to at least 2 or 3 people who've relocated their shifter with keisler's kit, and theyh have said the shifter that keisler includes in the relocation kit is cheap junk, just a word to the wise. Maybe pnhigg will tell us otherwise.

Yeah with the deep gears of the T56, and the tall tires typical of trucks, I would be looking at least 4.11's. I'm going to be running a 14 bolt soon with 4.88 gears. 4.88 sounds ridiculous for the street, but I'll be able to put it in 6th and cruise down the freeway at 70MPH with the engine turning just under 2,000 RPM. This should let me hole shot like crazy and still get good gas mileage cruisin.

the kit wasn't cheap but I don't remember the cost.
http://www.keislerauto.com/gm/gm-bar...page_tabs.html

Following is the link. If it doesn't work you can find it in the gm section of their website, then click on the 6 speed section, and scroll near the bottom. Their customer service guys are very helpful regarding swaps and such, so don't hesitate to call them if you think you might be interested in the shifter relocator.

On the gears...everyone has different preferences. With my little engine, and the mild cam, it likes to spin a little more than stock, so it actually doesn't like lugging under 1500rpm or so, so the 4.56 keep the engine spinning a little faster. Even so, 70 mph at 2000 rpm is not bad in my mind (I have 295/45 R18s on the back of the truck). I don't want to suggest anything too strongly, but I would not go with any gear higher than 4.10. I think you are going to want the lower ratio to get the truck moving.

FWIW I started with the factory 3.08 when I first put the engine transmission in. After a few months of shopping I found a good deal on an Eaton LSD with 4.56 gears and bought it. I could tell almost as much different (seat of the pants) when I changed the gears as when I changed the engine and transmission.

I agree with pnhigg on this one, if you stick a T56 in a truck, don't go with any gears higher (numerically lower) than 4.10. I'm still running around with 3.08's until I finish regearing my 14 bolt with the 4.88's and I'm expecting a night and day difference. 3.08 is a total mismatch for the deep 2.66 first gear of the T56.

[gl18rider]

Great info. Thanks guys.
The other item I'm not quite sure of is the speedo. From what I've read my T5 was 2k ppm and the T56 is 4k ppm and my speedo adjustments are built into the cluster in 88-89?