This probably isn't the best place to post this, but you guys seem to know the LS1's the best. Why is it that you can't bolt a LS1 T-56 to an old school SB when you can take a turbo 350 or 400 and bolt it on a LS1 with only 1 bolt hole that won't line up. I understand that it will take some kind of a different pilot bearing since the input shaft sits at a different depth. I'm pretty much convinced that it will bolt on, but there is some kind of issue with the input shaft to pilot bearing clearance. There might also be some kind of problems with the getting the clutch disk to fit on the splines correctly.

Can anyone point me in the right direction? Is there a better place to ask this question? There really isn't much interest in swaping the LS1 T-56 onto a Gen 1 SB, if all it takes is a custom flywheel or pilot bearing then I may go through the process of developing one.

 

For the amount of time involved and buying or making cutom parts it would probably be worth it to get the "aftermarket" T-56 and only have to get a few different pieces that will bolt up...

 

the bellhousing itself physically bolts up.

the clutch doesnt match... you'll need a custom clutch solution.

and you need to measure input shaft length.. i think it ends up being too short.

 

That sounds about right. I have the aftermarket T-56 and it uses all 5 speed bell, clutch and flywheel. It comes with an adapter plate to get the 18 degree rotation or whatever that the f-body uses. The only really PIA part is the driveshaft, you have to get one that is, IIRC, 1.9 inches shorter. Otherwise you can buy everything else rather than make custom stuff.

 

you can bolt a gen2 LT1 t56 to a gen1 small block however.. folks have done it on this board.. It would seem this or the conversion t56 are the best solutions rather than the LS1 t56.

edit: you guys are quick, posting this two others are already on!

 

The reason I'm wanting to use the LS1 trans is that it's about 500-700$ cheaper than the LT1 trans and about 1000$ cheaper than the conversion trans.

Like I mentioned in the T-5 to T-56 thread, I need to get the bell housing flange to input shaft measurements, as well as the pilot stub and splined section lengths. I think I might be able to mix and match clutch disks to get the right spline count....the problem will be making sure the clutch disk sits some where on the splines on the input shaft. I'm not too worried about making a pilot bearing. I have access to a machine shop and some really nice lathes. The guys I work with would be more than willing to help me out. I just need to see if the input shaft is going to bottom in the crank.

Would anyone be willing to get me some measurements off of their T-56?

Mr. Dude: I'm thinking it's going to end up too long. The reason is that when you bolt an turbo 350/400 to a LS1 it's too short, and you have to use a spacer on the flex plate to make it fit, does anyone have one of those spacers? The thickness of that spacer would be how much further the input shaft would stick into the crank......if I'm visualizing this correctly.

 

I think I read this somewhere else too. I know the LT based T-56's have shorter input shafts and I think the LS based ones are around the same length. Unforunately I dont have one to measure

 

If that is indeed the case, then all you would need is a spacer to space out the flywheel.

I had the awnser to my question in reach once, I met a guy, with a monte no less, that had gotten an LS trans by mistake, he some how managed to get it to fit with some sort of home made adapter. At the time I wasn't that interested in the swap so I didn't look into any further. He has since moved and I've lost contact with him. So I know it will work, but I'm not completely sure how he did it.

 

Ok, just got off the phone with my tranny builder. LSx based 6-speeds have a longer input shaft, the flywheels are much much thinner than the LTx based ones, the clutch itself is bigger than an LTx based clutch in diameter. So, you would have to have a spacer for the transmission made, an adapter for the flywheel made, and a custom flywheel to fit the clutch itself, which by the time you paid to have all that made, you probably could have bought 2 LTx based transmissions, or swap the input shaft from an LTx transmission in, then you have to use the older slave cylinder setup with an LTx bellhousing.

 

I may be wrong but Lakewood may already have the solution. You may want to call them. My aftermarket trans came with the adapter plate for the trans to bell, but i think I remember reading something about the LS based bell by lakewood. They may be able to make the spacer for you too since they should have all the designs for both tranny's

 

From the searching that I have done, I have found that the bellhousing of the LS trans is 5/8" shorter, the input shaft is the common 1.125 x 26 spline that will work with any chevy clutch. I haven't found how much longer the input shaft is than the LT trans, I'm kinda wondering if it is actually longer or if it's just the shorter bellhousing that throws every one off. I don't think I'll need to use the LS clutch and flywheel, there is just no reason to use a thinner flywheel. I think if you space out the trans so that the throwout bearing is in the correct place and as long as the clutch disk hits the splines (which there are over 3" of), then the only other issue is getting the pilot shaft to hit some sort of a pilot bushings.

I really appreciate your guy's help, please don't think I'm blowing you off, I just need actually measurements for it all to make sense in my head. Everyone is conviced you have to use a LS clutch with the trans and that in order to put the trans in an older vehicle you need to use a linkage style throwout bearing, I just don't think you do. I need to find some one with a LS trans sitting on the ground that can take some quick and dirty measurements for me.

In order for this project to make monetary sense to me I need to be able to
1: Use a stock Gen 1 flywheel and clutch
2: Use the LS hydraulic throwout bearing
3: Use a spacer on either the engine side, or trans side of the bellhousing

 

Well, from what my transmission guy told me earlier, the LSx based transmission just won't work on an older style engine, the LTx based one will only work...it all has to do with the input shaft and he's rebuilt probably over 100 of them and knows these transmissions inside and out.

Here, maybe this will help



It looks to me like the bellhousing on the LSx trannys are longer by about a little over 1 1/4 inches, thus making the entire transmission longer. The LTx bellhousing does not have the provision for the slave cylinder to come through the side if you were to use it, thus you would go back to the shift fork style slave cylinder. It also shows three different part numbers for the F-body trannys. One for the 93-97 one for the '98 and I bet one for the 99+ cars.

 

Like I said before I appreciate your help, but I want an "it won't work because the input shaft is xxx too long." I'm not trying to discredit your tranny guy, I'm sure he can build a mean tranny, I'm just willing to do a little extra fab and machine work than the average Joe to reach my goal.

If you look at the pic you posted, which I found earlier in my searching, you'll see that measurement B is 16mm longer on the LS trans both on the 98 and 99 models than it is on the LT models. This is .629" longer, I know from what you have said and every one else that the input shaft is longer on the LS, even if it's a full inch longer than the LT1 trans that means I only need a .37" thick spacer to get the input shaft right where it was with the LT1 trans. Of course now the trick is getting the LS slave cylinder at the right depth. I don't want to use an external slave cylinder, it complicates things and takes up exhaust space. It's easier for me to mount a universal clutch master cylinder any way. That makes the LS slave a perfect match for what I want to do.

So I'm left with needing to know the bell housing flange to input shaft distance and the bell housing flange to slave cylinder distance. I've got a lead over on ls1tech i'm following right now too.

 

Do you currently have a LS1 T56?

 

Nope, if I did I could figure it out myself. I'm looking for some one who has one that's out of the car.

 

So, why go through all the hassle and just get a LT1 T56? Am I missing something? There really isn't that big of a price difference between the two...not around here anyway.

 

As I mentioned earlier LS t-56's are going for around $400-$700 CHEAPER than the LT t-56's right now. This is from what I've observed on E-bay. Either transmission is pretty much non-existent around here. It didn't used to be that way but now that the old school hot roders are catching on they are getting scarce. The other reason is that I may go with an LS1 in the future so I would be all set up for that if and when I go that route.

Not to mention that I might be able to make a few bucks if I could come up with a cheap conversion kit for the budget concious.

 

As my grandmother used to say "Nothing to it but to do it". Looks like you have your mind set on this one already, why not get it and try? If it doesn't work sell it again, or hang onto it until you get your LS for the car.

 

Yeah that's how most of my projects end up. I would like some preliminary measurements that show that it's even close before I drop the coin. As long as I know the throwout bearing to input shaft tip distance in't too far off in the wrong direction from a gen 1 SB I can make it work.

Another one of my projects started out like this. I had read about the LS1 front brake swap on this site and decided that it was doable on a G-body as well. I got some naa, probbably won't work, it's not strong enough, blah blah blah. As far as I now I was the first to actually do that particular swap on a G-body. It's pretty common place now.

 

If you know the PN for tremec on the LS T-56 give Tremec a call. I have called a few times about getting my speedo to work correctly and find out what aftermarket shifter I needed for my trans. Sometimes they dont want to be very helpful, but at the very least they should be able to tell you where to get the .pdf with the correct specs for the trans you are looking at.
TTC: Contact Us

 

Dont know if you found your answer or not but I came across this tonight ATS. This should do what you are looking for. But I think you have to use the LS1 hydraulics?

 

Yahtzeeeeeee!!!!

Thats exactly what I was thinking of making, and these guys have it all figured out.

They even lay out the exact thickness of their adapter plate, looks like 3/8ths is the magic number. It also looks like their adapter package is little spendy. I'll be trying to make my own out of either some 3/8th's plate or an old engine block. Thanks for posting that.

 

I am running a LS1 T56 behind a Gen1SBC,so it CAN BE DONE.

I am running a stock,although aftermarket replacement Hays flywheel,CF DF clutch,Lakewood scattershield, and my stock mechanical clutch linkage in my '82.All of these parts are direct replacement parts or factory for the car.

From the bell back I use a McLeod #8-207 adapter plate to bolt the LS1 T56 to the Lakewood SS which is drilled for a T5 or T10 (the bell).I had to use a McLeod extended pilot bushing #8-1094 IIRC.The reason for this is that with the adapter plate on the bell it move the trans back to the point where the input shaft just entered the pilot bushing with very little support.With the extended bushing I now have 5/8" of input shaft support.I then made my own crossmember as to retain as much ground clearance as possible and hopefully leave room for the hooker LT y pipe I still need to make. I had to trim the shifter hole back around 2.5" and weld in sheet metal to close the rest of the hole up since it doesn't need to be so big with the T56.Aside from getting my driveshaft cut 4" , again I am swapping frm a T10 4 speed, I am mostly done aside from wiring up the VSS and Reverse Lockout.

This swap can be done with readily available parts.I have around $1800 into my swap minus the fluid and getting the DS cut,so add $150.All parts aside from the trans are brand new,although it was rebuilt when I bought it.

McLeod #8-207 $230
McLeod #8-1094 $40
Pro 5.0 $175
Misc pigtails $20
etc,etc

 

BMmonteSS, I know it has been a whole year but I was wondering if you made any progress on this? I am *thinking* of doing the opposite and putting a gen 1 trans on a gen 3 engine but I am wondering how you made out before I think about this too much more.

 

Unfortunately the project has died as I'm just waiting to swap the LS1 that's attached to the tranny I want.

What you want to do is pretty easy actually. All you need to do is bolt up the old tranny and use a spacer between the crank and the flywheel or flexplate.

 

Does that mean I would also need an extended length pilot bushing too?