irocdis

Hello Everyone,

I am planing on a T-56 Conversion out of a 98 LS1 to an auto 5.7 88 Iroc. I will only be taking the T-56 not the LS motor, I will be mating the T-56 to and older 2 piece rear main block. I am aware there are a few differences between 98-2002 T56 and 93-97 T56, pertaining to the Clutch setup and input shaft and Flywheel.

I've been doing my research but I have a few question and I'd like to make sure.

Can this conversion be accomplished with a 98 T56 or are the differences an issue?

Which year is preferred for conversion and why?



Is there anyway to make the mechanical stock speedo work with electric speedo control of t-56?
I guess i can use this:

http://www.abbott-tach.com/cablex.htm


OR CHECK THIS OUT!!!!! ANYONE EVER USE THIS BEFORE?

http://www.swfabrication.com/product...products_id=28

Actually I think I answered my own question.

http://www.t56cablespeedometer.com/



Any other issues I should Expect?


Is this the only Flywheel that excepts a 2 piece rear main style crank for the conversion?

http://www.summitracing.com/parts/ctf-700107/overview/

Keoman

iTrader: (3)

98-02 T56 can be used provided you swap the bell housing, mainshaft, etc

Preferred trans for the swap is a 94-97 T56. The 93 trans has many proprietary parts and also a steeper 6th gear.

For speedo control, you can either go through the headache of getting a converter box or PM a member here, Alloy, and get your tail housing converted. (best option by far)

Took me 2 days with all the parts, just make sure you have everything before you start.

cuisinartvette

Having done the LTx T56 swap Id say do the LSx one you avoid the whole hydraulics/release issues some of the LTx style setup can have.

dabomb6608

iTrader: (3)

If you go LS style route you have the option of using the adapter plate and extended pilot bushing to be able to use your original T5 bell housing/clutch setup. That is the route I plan on taking. McLeod makes the adapter plate as well as another company I cant think of right now. Can be found on summit I believe....bingo here it is http://www.summitracing.com/parts/mcl-8-207/overview/

irocdis

Please explain LS route. Yes the t-56 is original from an 98 camaro with an LS, but I'm only taking the Trans and mating it to an older L98 with a 4 blot main and a 2 peace rear main.

FYI, This T-56 has been around, The last motor it was mated too was a 95 LT1 (ex coworker). Trans is Rebuild and Health, But I'm not sure on what was change to get it to mate to the 95 Lt1. I guess first I need to identity what was changed if anything.

From what I gather the best way to tell the 2 trans (t-56) a part is form the style slave cylinder.

The LT1 T-56 has it mounted outside on the drivers side.

The LS1 T-56 has it mounted inside.

Correct?



FYI. I don't think LS style T-56 requires this Flywheel

http://www.summitracing.com/parts/ctf-700107/overview/

dabomb6608

iTrader: (3)

Definitely figure out exactly what you have before making any guesses. Who knows what was done for it to mate to a LT1, if I had to guess I would say the front cover/input shaft was changed to work with the LT1 and LT1 clutch style setup. Check out this site, lots of good info on it. http://www.skulte.com/T56.html

Take straight from the above site,

"Differences between the '93-'97 f-body, 98+ f-body, and Aftermarket T56

1993 to 1997 LT1 F-body T56
Same length as T5 and 700R4, so you can re-use your same 27 spline driveshaft, torque arm, and bushings
Electric 17 pulse per driveshaft rotation VSS (Vehicle Speed Sensor)
LT1 pull-style clutch, bellhousing, and slave cylinder is necessary

1998+ LS1 F-body T56
This is from the LS1 f-body, so it has a different length input shaft, and a completely different push-style clutch setup. The throwout bearing is a hydraulic unit that eliminates the clutch fork. To change this transmission to work with the LT1 clutch and bellhousing, you will need to replace the input shaft as well as the front cover of the transmission case (because it does not have the clutch fork pivot). An LS1 master cylinder might be necessary. The case and tailhousing dimensions are identical to the LT1 T56.

Retrofit T56
The major benefit to the Retrofit T56 is that it allows you to use a standard style clutch and bellhousing. It also has a mechanical speedometer sender which is similar to the 700R4 & T5 transmission (an electric 700R4 & T5 VSS will bolt right in). The draw backs are that the transmission is 1.9" longer, so the driveshaft and torque arm must be shortened. It is available new from Tom Sallee at Sallee Chevrolet for $2295."



Now, with the method I refered to in my first response, you use the adapter plate to mate a regular ole T5 bellhousing up to the T56 case. It obviously goes in between the two. With it being .5" thick (if weight is a huge concern then look for a different way) you HAVE to use the LS1 input shaft. The LT1 would never be long enough and wouldnt have any support at the end of it (IE meet up with the pilot bushing). Even with the LS1 shaft you still need to use the extended pilot bushing so it has plenty of support.

That bushing is seen here:
http://www.thegearbox.org/catalog/it...17/6239106.htm

That is the site I first saw the adapter plate on. Here is the one they sell:
http://www.thegearbox.org/catalog/it...17/4803441.htm

Hope that helps explain alittle bit more.

irocdis

Yes I am familiar with this article/website .Thank you.

However, he does not state why you would want to convert an LS1 push style back to an LT1 Pull style setup.

From what I understand the LS1 input shaft and clutch setup Fits to mate to old style 350 L98 2 piece rear main. The only thing you would have to change is the flywheel.

Will I need this Quicktime Bell housing to make it all work?

http://lakewoodindustries.com/ls1-to-ls1-t56-chevy.html




Correct?

jmd

iTrader: (4)

That particular one is for LS to T56, so it's shorter than what you'd need to use the T56 with a Gen I SBC.

Even so, it then becomes a longer overall transmission assembly and you're putting the shifter a bit farther back, as well as more than likely requiring a driveshaft. Some driveshaft shops will have a minimum shortening distance (to get away from previously welded tubing) so that's a whole new driveshaft, which is more $ than a shortening job.

If you're staying SBC, you can source used LT1 input & front plate for less $ than you can sell the LS1 pieces for.

The only 2pc. L98 was 1985 Vette; anything 86-up is 1-piece and accepts the 93-97 F LT1 T56 flywheel.

It all depends on what parts you have and what parts you want to maintain / be compatible with. In short, you need to make a list of parts you have and use it to determine what each option would cost.

irocdis

Any good places/web sites I can find used LT1 input & front plate and fork?

How much shorter is T-56 with LT1 style Pull clutch/ Bell housing? 2inch?

dabomb6608

iTrader: (3)

Well you can look in junk yards/ebay/classifieds/post up a wanted on here and LS1tech.com's wanted forums.

You might even be able to find someone to trade their LT1 input/plate/fork for your LS1 plate/input.

scottwrightF1

iTrader: (2)

You can use this Quicktime Bell housing with your SBC engine if you are going to use either mechanical clutch linkage or hydraulic setup:

Mechanical fork:
http://www.summitracing.com/int/part...23pb/overview/

Or

Hydraulic:
http://www.summitracing.com/int/part...6023/overview/

Or

You can use a stock T5 bellhousing and just get a 1/2" adapter plate.
http://www.thegearbox.org/catalog/it...17/4803441.htm

There might be other brands for bellhosuing for the setup.

Will you have to swap out your front LS1 midplate for the Lt1 if you are going mechanical fork setup.

I am setting up my SBC with the QT 6023 hydraulic, but not done yet. I am swapping out my front LT1 midpate to the LS1 and won't need the Lt1 midplate and 1/2" adapter plate. I will sell the LT1 midplate and 1/2" adapter plate when I am done setting it up. The Lt1 midplate and 1/2" adapter has never be used so the parts are new.

Hope this helps.

irocdis

Thanks,

Turn out in gona go with LT1 t56 with Pull clutch and Lt1 Stock Bell housing. That should fit right?

Also is the stock Iroc drive shaft 28 spline ? I don't know if it makes a difference but I have a 9 bolt in the car.