Swapping from BBC to LS3, Can I Keep the T56?

[MaxHarvard]

Originally Posted by glassman

I converted my T-56 from an LT1 version to an LS version, There is a kit i bought from a company back east (Rockford i believe), bout 400$, includes a new input shaft, shims, and front "collar" which you'll need. I saw an article about this, either popular hot rodding or chevy hi-performance, which is why i did it...

http://www.gmhightechperformance.com...on_conversion/

I'm pretty sure if you have an t56 behind the bbc you'll need a different input shaft (as the final length is different) and collar, the lt1 tranny bolts up to a sbc, and the bolt pattern is the same for a bbc. You'll also need to confirm your bellhousing (you'll need an ls one obviously)

I'm glad everyone didn't think my article was pointless. I got a lot of flak on that article for some reason.

[Che70velle]

So the t56 magnums have a different input shaft length than the std, t56?

[Mkelcy]

Originally Posted by Che70velle

So the t56 magnums have a different input shaft length than the std, t56?

There are two "standard" older T56's for Chevy's - the LT1 T56 and the LS1/Magnum T56. The LT1 T56's have about a 5.5" input shaft - engine to bell housing to bell housing to transmission mounting surface; the LS1/Magnum's have about a 6.5" input shaft measured the same way. The Magnum should bolt right up to an LSx engine with the right bell housing and pilot bushing.

[Che70velle]

Originally Posted by Mkelcy

There are two "standard" older T56's for Chevy's - the LT1 T56 and the LS1/Magnum T56. The LT1 T56's have about a 5.5" input shaft - engine to bell housing to bell housing to transmission mounting surface; the LS1/Magnum's have about a 6.5" input shaft measured the same way. The Magnum should bolt right up to an LSx engine with the right bell housing and pilot bushing.

You are correct. The lt-1 t56 will bolt up to a sbc, or a bbc, with no problems.
The LS-1 t56 won't bolt up to a sbc, so I'm guessing the op has a t56 magnum built for a sbc/bbc application, which as you stated, has a shorter input shaft. I know that I had to convert mine over.

[Mkelcy]

Originally Posted by Che70velle

You are correct. The lt-1 t56 will bolt up to a sbc, or a bbc, with no problems.
The LS-1 t56 won't bolt up to a sbc, so I'm guessing the op has a t56 magnum built for a sbc/bbc application, which as you stated, has a shorter input shaft. I know that I had to convert mine over.

No. The LS1/Magnum T56 has a roughly 6.5' input shaft which will work just fine with an LSx engine, given the correct bell housing.

[glassman]

Originally Posted by MaxHarvard

I'm glad everyone didn't think my article was pointless. I got a lot of flak on that article for some reason.

You mighta got some flak for that, but out here in Kali, your secrets out. The guy i sold my zz3 to bought an LT t-56 and i couldn't be happier as I had my t-56 "magnumed" rebuilt right before my LS conversion and i was sooo relieved when i found out i could do this ( i was afraid i was going to be out another 1600)

So ya, thanks for that article. Watched your blue hour build too, absolutely love your car....

back on topic,,,,sorry for the diversion......Mike

[MaxHarvard]

Originally Posted by glassman

You mighta got some flak for that, but out here in Kali, your secrets out. The guy i sold my zz3 to bought an LT t-56 and i couldn't be happier as I had my t-56 "magnumed" rebuilt right before my LS conversion and i was sooo relieved when i found out i could do this ( i was afraid i was going to be out another 1600)

So ya, thanks for that article. Watched your blue hour build too, absolutely love your car....

back on topic,,,,sorry for the diversion......Mike

Well good! I'm glad someone got something out of it. I figured for $400 and if you have an LT T56 laying around, it only makes perfect sense.

The one I built for the article was one I had from my old build. I converted it and sold it for double!

[Mkelcy]

Originally Posted by Che70velle

You are correct. The lt-1 t56 will bolt up to a sbc, or a bbc, with no problems.
The LS-1 t56 won't bolt up to a sbc, so I'm guessing the op has a t56 magnum built for a sbc/bbc application, which as you stated, has a shorter input shaft. I know that I had to convert mine over.

An LS1 T56 will bolt up just fine to a SBC/BBC with a 0.5" thick mounting/adapter plate and the original Muncie type bell housing and mechanical clutch linkage. You can skip the adapter plate if you use a hydraulic clutch linkage and a T56 specific bell housing for the SBC/BBC.

[Che70velle]

Originally Posted by Mkelcy

No. The LS1/Magnum T56 has a roughly 6.5' input shaft which will work just fine with an LSx engine, given the correct bell housing.

Correct again. The standard GM t56 bell will work, as well as others built for this application.

[Che70velle]

Originally Posted by Mkelcy

An LS1 T56 will bolt up just fine to a SBC/BBC with a 0.5" thick mounting/adapter plate and the original Muncie type bell housing and mechanical clutch linkage. You can skip the adapter plate if you use a hydraulic clutch linkage and a T56 specific bell housing for the SBC/BBC.

I've seen this done, but never in high power applications. I wouldn't run it, ever.
Back to the original question from the op, he never stated he had the adapter plate, and associated hardware. He simply wanted to know if his tranny that's currently behind a bbc, would work behind an ls3.