Formula383

iTrader: (8)

I took a little time the other day to do a small write up about converting my LT1 T56 to use an LS1-style clutch. I've had a few ask about the process and parts involved, so I figured I would just write it down to share with everyone.

http://www.formula383.com/2011/10/05...56-conversion/

It's not a step-by-step manual but rather more of a story of my experience with conversion, some recommendations and a parts list. Hopefully this will help others who are considering the swap or just curious what it's about.

97FormulaWS-6

iTrader: (1)

Sweet... I'll have to save this as I was wondering/hoping to do this when I put my car back together.

ZFreie

Interesting, I might have to look into this when and if I go 6speed. Whats the main advantage to the ls1 vs lt1 clutch, better design and stronger?

97FormulaWS-6

iTrader: (1)

Shortening the input shaft 0.500" would achieve the same thing as the bell-housing/tranny spacer, or would this reduce the room for the clutch such that it wouldn't work?

Any adverse issues with the shifter location in the car with the 1" shift of the tranny?

Formula383

iTrader: (8)

Personally, I would rather use the spacer. The longer LS1 input shaft provides a greater area of the splines as compared to the LT1 inputs shaft and you will want most of that especially if you want to use a twin disc setup.

As far as moving the shifter back, I only had to trim a little more from the opening in the trans tunnel. It clears the center console fine and I've already gotten used to the feel of it being closer.

97FormulaWS-6

iTrader: (1)

Hmmm... I wonder if TDP (?) would be able to extend the splines back further while shortening the shaft to fit. Then the only issue would be the height of the Throw-out bearing.

I saw the picture of the spacer you had to use, I'm assuming this was to bring the face of the throw-out bearing forward to properly engage the pressure plate?

Formula383

iTrader: (8)

I think most places will say, including what I was told from Liberty's Gears, to not mess with machining, cutting, welding on the input shaft unless it's absolutely needed. The shim was needed to get the gap between the bearing and pressure plate within 0.100-0.300 per McLeod's instructions.

97FormulaWS-6

iTrader: (1)

Cool. Thanks for the info! I was hoping I could do something like this, with the SSR output shaft on the T56 it looks to make a fairly stout tranny.

97pontta

iTrader: (10)

Interesting swap. Is the main reason for LS1 slave swap to better release at higher RPMs?

Formula383

iTrader: (8)

Not really. First reason is the LS1-style design of the Street Twin is less-likely to fail under high horsepower, high rpm applications. Second reason is greater availability and selection of clutches.

merim123

iTrader: (11)

Kudos for putting this together! Two questions:

1) where did you get the mid plate from? The TUE part number
2) Can you elaborate a little on this quote I took from your writeup:

I know that changing the input shaft to the LS one requires this change, but how do you go about it exactly? Is that what this shim kit is for?

Tremec Shim Kit TRS394225K 45.99

Formula383

iTrader: (8)

You can get the front cover from Liberty or RPM or even off of a junk or spare parts T56. When you change the input shaft, you will need to check the end play or preload and use the shims from the shim kit to get the correct amount of end play.

If you are just doing the input shaft, it's pretty straight forward. Unbolt the old front cover, swap input shafts, replace the bearing and race, set endplay and bolt the new cover back up. I ended up replacing the 3-4 synchro assembly and we had to take the whole transmission apart.