LS1 T56 vs. LT1 T56 for combination with SBC 383

[Tim_in_NC]

Guys,

I'm sorry if this has been asked before, but I could seem to find an answer...

I've got an opportunity to purchase a '99 LS1 T56 for a reasonable price... Should I jump on this or look for an LT1 T56...

Are there any issues with the LS1 T56 that make it more difficult to mate to my carbed SBC 383 ???

Thanks in advance...

TIM

[68protouring454]

tim, they are basically the same tranny strength wise, however the ls1 will not work with a older generation motor (lt-1, back to 2 peice rear main seal motor) unless you install a shorter front shaft and a different bellhousing, for those reasons iwould just look for a lt-1 t-56, preferably a 97 case
jake

[Tim_in_NC]

Thanks... for the info...


TIM

[Mkelcy]

tim, they are basically the same tranny strength wise, however the ls1 will not work with a older generation motor (lt-1, back to 2 peice rear main seal motor) unless you install a shorter front shaft and a different bellhousing, for those reasons iwould just look for a lt-1 t-56, preferably a 97 case
jake


Sigh. The LS1 T56 is easily adapted to an early small block. And if your engine is not internally balanced is preferred.

A Muncie input shaft is 6.6 inches long. The input shaft on an LS1 T56 is about 6.5 inches long, but the T56 won't bolt up to a standard Chevy bellhousing . However, McLeod Industries sells an adapter plate (like the one used on the Aftermarket T56) which allows the T56 to be bolted to a standard Chevy bellhousing and is about 0.5 inches thick. They also sell an extended pilot bushing which makes up the 0.5 inches lost to the adapter plate. Both parts together are about $175. With this setup you can run your current bellhousing, mechanical clutch linkage, flywheel and pressure plate (if you don't have one already you'll need a 26 spline clutch disk), and can use a scattershiled if you want to.

[1976SR71]

Here is an article with good info.
http://www.hotrod.com/techarticles/43599/index.html

[68protouring454]

i still think guys reccomend just using the lt-1 t-56 and getting rid of all these adapters, adapters = weakness
jake

[Mkelcy]

i still think guys reccomend just using the lt-1 t-56 and getting rid of all these adapters, adapters = weakness
jake

I guess you get to chose your "weakness." The adapter plate is 0.5" thick steel. It mounts to the bellhousing using the original Muncie mounting points, and mounts to the T56 using the same T56 transmission-to-T56-bellhousing mounting points that the LT1 uses. It is also the factory engineered way of doing this swap. In addition, I'm not aware of any scattershields for the LT1 T56 application. Myself, I prefer hydroformed steel between my legs and the flywheel/clutch rather than cast aluminum. Either will work.

However, if cost is also a factor, the LS1 swap is also cheaper. Even if you already have a manual transmission in the car, to use the LT1 T56 you need (i) the factory hydraulics (which often come with the transmission), (ii) a bracket to mount the hydraulic master cylinder, (iii) a "pull" style clutch, (iv) a flywheel that accepts the "pull" style clutch, (v) a cross member and (vi) a shortened drive shaft. If your 383 is not internally balanced, you also still need the external balance plates. I believe that the clutch parts alone will set you back more than $500, even if you make all of the other parts or get them with the tranny.

If you already have a manual transmission in the car, to use an LS1 T56 you need (i) the adapter plate, (ii) the extended throwout bearing, (iii) a cross member and (iv) a shortened drive shaft. The adapter and pilot bushing are about $175.

I don't care how people do this swap, but if you have a lead on a good LS1 T56 for a good price, there is NO reason not to snap it up and use it in your car using readily available and inexpensive parts.

[68protouring454]

consider me learned!!lol

[Tim_in_NC]

thanks guys...lots of good stuff here...
It's nice to learn from the experienced...

TIM

[Brandon]

Any one know what the McLeod Part # is for the .5" adapter plate?? I need one to adapt a T56 (LS1) trans to my SBC 383 (Gen 1).

I have an external balanced 400 flywheel and a 26 spline clutch disc.

My car is a 1969 Camaro.

I have tried to contact McLeod (Red Roberts) but I cannot get him on the tech line.

Has anyone bought this adapter and extended pilot bushing?
What are the part #s?

I also need a crossmember :-)

Please help,
Brandon

[rmadsen]

MKelcy,

Where can you get the MCLeod Adapter and bushing for $175? So far the best price I've been able to get is $228 for the adapter and
$34 for the bushing from summit. Is there a better source?

[Mkelcy]

MKelcy,

Where can you get the MCLeod Adapter and bushing for $175? So far the best price I've been able to get is $228 for the adapter and
$34 for the bushing from summit. Is there a better source?


Got mine direct from McLeod.

[rmadsen]

Are you a vendor? Because the price McLeod quoted me was a bit above the summit price?

[Mkelcy]

Sorry, not a vendor. I got my parts very early on in McLeod's production, the price may have gone up since then.

[WS6]

just to throw this out there, but could your setup or inteneded use benefit from the lower first gear ratio found in a 93 T56?

not sure how much harder it would be to adapt it if any. id venture to say it is the same as the other LT1 T56's. just a thought.