TFS355S10

I searched everywhere and still haven't come up with an actual answer to this.

Is there a way to put a T56 behind a 99-00 model 6.0, (with the "long" crank), other than swapping to crank out for the newer short version?

TipsyMcStagger

iTrader: (1)

Info

TFS355S10

Bunch a quitters..... lol

Thanks for the research Tipsy! Even though that all seems like bad news for me. Not to big of a deal though I guess. Won't be the first time changing a crank, n probably won't be the last either.... lol

TFS355S10

Somewhere I read that some of the 4.8's might have had the long crank also. Any truth to that? I'm guessing they had the infamous spacer.

daytripper67mi

LT1 T56.....should be cheaper also.

iliveonnitro

I'm in your boat. In the middle of swapping cranks, now.

TFS355S10

I read one thread where somebody was going to use a LT1 T56. Redrill a LS flywheel to fit the LT1 pressure plate and use a LT5 clutch disc. I never seen a follow up to se if it actually worked though.

It sounds like it could work that way except for the starter. I'm not sure the starter would still engage the flywheel since the flywheel would be .400 farther toward the rear.

And then there's the part about the POS design of the LT1 clutch.... LOL

Is that what you're referring to, daytripper?

hookemdevils22

iTrader: (12)

Just did it with an LS1 F-Body T56 my Nova. Call McLeod, and check out page 20-21 of my build. It takes a .500" spacer between the bell housing and trans and an adapter flywheel that should now be on summits website (I had to call to order, they said they'd add it). Pilot bearing is the LS1 F-body, NOT 2007(?)-newer style I was told I needed. The truck starter worked perfectly, too.

Edit: to be clear, you do NOT have to swap cranks.
Page 20 from my build: https://ls1tech.com/forums/showthread.php?t=1032289&page=20

TFS355S10

Sweet! That's some good news. Flywheel is on summits site. I just googled the part # and their website came up. A little spendy, but prolly about the same or cheaper if ya add the cost of a crank swap. LOL

Those spacers seem to be originally for a LT1 style T56?

Think I'm gonna order one of those flywheels (asap) and do some experimenting... Thanks hookem!

TFS355S10

Just out of curiosity, did you happen to take pics of the front side of the flywheel? No big deal, just thought I'd ask. LOL
I'm gonna see one in person soon. LOL

TFS355S10

100 bucks a piece for those spacers. Ouch!

I did find that, (Mcleod), does offer a few different thicknesses of those spacers. 1/4", 1/2", and.7. Also with different clockings for the hyro connections/fork or no opening at all.

Since I already have a LT1 T56 in my truck now, I've been pondering this;

We know the LT1 T56 input shaft is shorter than the LS1 version, but the bellhousing for the LS1 is also shorter than the LT1 version, so that put the pilot bearing in about the same position relative to the engine block/bellhousing mounting surface. (I don't know the exact measurements here so I'm just thinking out loud)

Since hookem used the LS T56 and had to use 1/2" spacer to get the proper pilot bearing engagement, (small pilot bearing in the traditional spot in the crank. #1 in the pic linked below), I'm wondering if I could use the, (short input shaft), LT1 T56 and one of the bigger pilot bearings in the "rear", (position #2 in the pic link), position of the crankshaft to get the proper, (somewhat?? LOL), pilot bearing engagement?

Basically moving the trans 1/2" forward, (Compared to what hookem did), and the pilot bearing 1/2"? or so rearward to make up for the difference in the trans input shaft length.

I realize all this leaves the throwout bearing issue completely out in the breeze, but I have an idea or two on that if the actual trans, pilot bearing, flywheel would work.

http://img152.imageshack.us/img152/7...jdelijkiv6.jpg

Let the flaming begin... LOL

hookemdevils22

iTrader: (12)

Sadly, no pics of the front side.

McLeod gave me a PN for the LS1 T56, but they stopped making it for some reason. So those that I bought have a single cutout for a shift fork. I modified them to account for the slave bleeder, which isn't a big deal since they're aluminum. I paid $140 for the pair, which is described as a .500" spacer (it's actually 2 x 1/4" spacers), and $320 for the flywheel. Yeah it hurts, but it beats swapping cranks.

You can also find extended pilot bearings - McLeod's is ridiculous at $40, but I've seen them referenced for $15 or less. I'd measure the input shaft depth relative to the bellhousing, then use that to calculate the necessary pilot. My input shaft is effectively .100" further aft relative to the pilot than an OE LS1 application (.500" spacer less the .400" thicker crank flange), but the 2007-later pilot DID NOT WORK, as it stopped my trans ~.500" from the engine. Given that the OE pilot is 3/4", and assuming that entire space is used to house the input shaft nose, I basically lost less than 1/8" of pilot engagement and still have, say .650". True, I forgot to measure, but I ran the numbers and I'm fairly certain that I'm good.

Edit: Also note that the newer style pilot bearing has a .894" ID, vs. an ID of .593" for the LS1 F-body pilot. Check out Rock Auto (use the LT1 trans application) or measure your input shaft pilot diameter - I'd bet that it's .593".

TFS355S10

No pics, no problem. Lol

Yea, the $500 price is a little on the spendy side, but not all that much more when you add up what it'd cost to swap the crank and a normal ls1 flywheel. Maybe actually cheaper. I haven't added up all the parts yet, so I cant say.

In my case I already have the LT1 T56 so the added expense of converting it to ls spec is, (close to $600, ebay prices), what I'm attempting to get by without. Lol

As for the input shaft pilot dia. It's the same on both versions of the T56. Mine is already in my truck and being driven daily so I can't do an actual measurement, but I used the regular old small pilot bearing like the old sbc has used for yrs when I put it together. The clutch kit actually came with a new bearing and a oldsstyle bushing. Both the same size so I used the bearing.

I think McLeod, (or somebody), must've mixed up part numbers on the later style bearing. I have seen a pilot bearing used it the #2 position with the correct ID. I'll see if I can find the part number gor it. I think it was in an Advance Adapters NV4500 swap catalog iirc. I'll look and post back.

AKAFRED

iTrader: (1)

cant you just make a spacer that goes between the block and transmission? guess the starter may not reach..

TFS355S10

Advance Adapters list a couple extended pilot bushings, (Bushings, not bearings though)

O.D. I.D Length
# 716154 1.090 .590 1.00
# 716161 1.090 .590 1.50

Just a question about the pilot info above. In the pic the "new" bearing, (left), looks to be the same ID as the "old" bearing. (Just by looking at it)
Definitely doesn't look to be .894 ID compared to the 1.09 OD of the "old" bearing. Typo?


Personally, I don't see why not. It would accomplish the same basic thing as the spacers used between the trans and bellhousing. Might be more likely to cause trans tunnel to bellhousing clearance problems, but internally it would be the same.

TFS355S10

Been reading the LS swap manual in the link above. I think I might have figured out something on the 05+ pilot bearing.

The swap manual states GM changed the pilot bearing in "SOME" GM vehicles in 05, specifically the C6's.

Didn't the vettes have the rear mounted transaxle by then?
I don't know much about later model vettes... LOL, but I think that may be where the new and old pilot bearing info gets confusing.

Hope ya don't think I' picking on you hookemdevils22. I'm not. I'm just tryin to get this all straight in my head. LOL

Another thing that caught my eye in the swap manual, and I don't know why this didn't register on my feeble mind before, but our "long crank" 6.0 has the same crank flange to bellhousing mounting surface dimension as the old SBC.
This tells me that if I bolt my LT1 T56 up to my "long crank" 6.0, the pilot bearing should be at the proper depth in relation to the trans input shaft.
A I deciphering this correctly?

If so then add the McLeod flywheel (# 460537) and LS style "push" pressure plate and all I have to figure out is a throwout bearing and fork.

hookemdevils22

iTrader: (12)

Not at all. I love trying to make a square peg fit in a round hole. And since it seems that most people simply say 'sell the LT1 T56, buy an LS1 T56,' I'd rather figure out how to make it work.


It likely could be. I used the Rock Auto catalog as a reference, so if they typo'd it in one place it would reflect the error everywhere the 'new-style' bearing is used.

Correct. The early LQ4 is great for mating to an older trans for that reason - I completely forgot about that. Thus I'd you should be able to use the early-style pilot and a probably an OE LS flywheel, which would work with your truck starter. According to this thread, the bellhousing appears to bolt up, though it seems that people are still insisting that the input shaft needs to be replaced. At the very least, your clutch and flywheel situation would still be up in the air, however.

TFS355S10

Hahaha. My sentiments exactly!
I suppose you already know how many times I've heard the "'sell the LT1 T56, buy an LS1 T56" thing. LOL


LOL. That thread is funny...

Yea the LT bellhousing and LS bellhousings share the same bolt pattern on the engine block side, (Same old bolt pattern as chevy has had for yrs, but missing a bolt on the right side on the LS, along with using the top center bolt), but I'm not sure about the trans to bellhousing pattern.
I'm pretty sure it is the same also, but I'm pretty sure the actual depth of them are different

I think I'd still need the McLeod flywheel to mate to the starter though since my flexplate is dished instead of flat like the other LS engines, (as far as I know)
Better way of looking at it is I think the starter is the same, so they "dished" the flexplate to keep the ring gear in the same relative position as the other LS engines?

Again, I may be way off here because I've never seen any other LS flywheel or engine in person. LOL

hookemdevils22

iTrader: (12)

Correct.

I've got an OE LS flywheel. I'm obviously never going to use it, so if you want it PM me with your address and pay shipping. At the very least you could use it to compare and get some ideas.

TFS355S10

Hell yea! PM on the way!

I'll see what I can do with it. If I can't use it I'll pass it along to the next guy.

Thanks!