drptop70ss

iTrader: (21)

I have a 65 cutlass that I have swapped an LT1 T56 into. It runs great but I am considering upgrading to an LS engine in the future and want to keep my T56. I have read that there are crank spacers available to work with gen I transmissions, does this mean that I could space out the flywheel and use my LT1 parts? Or would I need to use the spacer and an LS version flywheel/clutch/bellhousing with the LT1 trans? I am hoping this is possible since I have a few more LT1 T56 transmissions for future use and it would be easier to use them than try to find LS versions of the T56.

Shawn MacAnanny

iTrader: (12)

It depends on how much you want to spend. You would have to replace your input shaft, the bellhousing (the bolt patten lines up but one is 'deeper'. The ls1 also uses an internal clutch slaver cylinder.

drptop70ss

iTrader: (21)

so basically no way to do it without changing the input shaft, correct? Sounds like it is a no go.

Shawn MacAnanny

iTrader: (12)

As far as i know. I've never personally compared them but from everything ive read its the wrong length. See when you bolt an SBC transmission to an LS1 you need to use a spacer for the torque converter. This work fine. I dont see you being able to space a flywheel. And you can space the pressure plate or it wont work. I would just say no.

drptop70ss

iTrader: (21)

ok, just found some pics on site where someone changed the input shaft to an LS1 style, looks like it was possible to do this by taking the front of the trans off only and not having to tear it all apart. If this is the case then it is not too big a deal, I will look into it.

Verz

iTrader: (21)

Link to site? Im tossing this idea around and I too would like to see how its done to see if its worth it to keep/fix this trans or just get a LSx t56 if i swap.

crookedbowtie

Yes it is possible, I am in the middle of a conversion. Not to an LS motor, but I have to change to the LS input shaft. As long as your LT T56 trans is not a 93'/ early 94' F body and you pull the front cover to verify that you don't have a 29 tooth input shaft an LS1 input will fit directly in and an LS1 bellhousing/slave cylinder will mate right up ( all the T56's use the same bell to trans bolt pattern, but the bell to engine patterns and depths are different...hence the longer LS input shaft. The base trans are all interchangeable, though the Vipers have a bigger input/output shaft, and the early 93'/94' F bodies use a different gear set that is not interchangeable with the LS and later LT input shafts.

Pop N Wood

iTrader: (1)

Sell that t56 and buy an LS version. The LT type trans should be worth more since they made so few of them and they bolt up to the first get SBC stuff. Can't believe you couldn't make a trade somewhere and end up dollars ahead. Although I know dealing in used transmission is always a risk. Something about a failing trans can make people less than honest.

crookedbowtie

The LT T56 trannys are not worth more than the LS T56s. I found that they were actually cheaper and after the $200-250 input they about equal out and sometimes you can recoup a little by selling the LT input and bellhousing. They are the exact same trans from where the bell housing bolts up, minus the input shaft, back. If you are planning on running a lot of power it is a good idea to replace the input and run a scatter shield anyway. Yeah, they bolt up to the Gen 1 stuff, but you have to do a hydraulic clutch conversion and use the infamous LT1 pull clutch and a scatter shield isn't available. If you want to do manual clutch linkage there is an adapter setup available to use a standard 1st Gen SBC scatter/bell and opens your options up to any aftermarket performance clutch for a gen one and you can use your stock pedals and linkage.

As for already having the LT trans, I would just buy a new input and locate a Ls bellhousing. Should be pretty simple and cost effective in your situation.

the_merv

iTrader: (88)

You are missing some info there crookedbowtie..

Internally the 1994-1997 LT1 Trannies are the same. The dfifferences are the Input Shaft, and the Front Cover Plate.
The difference in the Front Plates are the LT1 one has the slot for the Fork, and the LS1 one has the 2 slots for the Slave Cyl, and the spot in the Center of it around the Input Shaft to bolt the Slave to.
The LT1 Front Plate will not work with a LS1 setup, and a LS1 Front Plate will not with with a LT1/SBC setup.

A few people have switched the Input Shafts and the Front Plates to get what they need, but that isn't necessarily good because the Bearings have to be shimmed correctly.


I would look for an LS1 Transmission.

crookedbowtie

Mcleod told me the front covers were the same, but I am sure you are right. Those differences didn't matter for the adapter that I used for the Gen 1 manual linkage/old bell conversion, but good to know for the future...thanks. The LS and LT front cover will both work with a Mcleod adapter to a Gen 1.You can get away with swapping to the LS input and not changing the front cover on my conversion, and the spacing checked out great on mine, but if you have to change the front cover and the input you are right, you may run into a problem, not to mention the input gear may be a little bit noisier because it doesn't "know" the other gear. I still don't think an LT it is out of reach for a budget LS conversion since he already has the tranny and front covers/bells/ and input shafts are available for a decent price.

bownarrow

Hi,

It looks like a lt-1 t-56 on a ponti 400 is possible, but hopefully someone can set me straight.

I don't believe a pull type flywheel is available for ponti engines, so manual linkage using a stock ponti flywheel could be used with a 26 tooth clutch.

I could use a stock bellshousing but would need an adapter: t-56 to old bellhousing.

Does it look like I would need an ls-1 input shaft - or is there an extended input shaft bearing somewhere?

Thank you for any help, pontiac always makes things hard. (The lt-1 t-56 is new, and has been sitting on the shelf for 9 years)

Dan

drptop70ss

iTrader: (21)

thanks for all the info guys, do you generally find the LS1 T56 trans parts available used frequently? What is the price range for a good used front plate, input shaft, and bellhousing?

ken125

iTrader: (3)

its not hard i bought an ls1 tranny when 2nd gear went out in my lt1 and just swapped it out it was easy.