Patrick007

Okay here's my story. I'm pullin the 305/700R4 outta my 89 RS and starting from scratch. I'm buildin a nice 350 (2 piece main) which should be around 400 BHP (upon dynoing). I would like to back this with a T56 out of an LT1 4th gen. Now my machinist had recommended the 1LE flywheel to me (10.4" clutch, 12.75" OD, 153 teeth, 15 lbs for those who don't know) which I have purchased. Now today I called up centerforce and inquired about a clutch/pressureplate combo that would work for this swap. They informed me that it couldn't be done this way. Now my question is... what do I do. I want to use the LT1 T-56 with this motor, but I guess I can't use the 1LE flywheel? So basically what I'm asking is.. what flywheel and clutch/pressure plate combination will I need to make this work. Again I would like to go with a Centerforce Duel Friction. Thank you guys for all the help.

PS - I guess I have a flywheel for sale if I can't use the 1LE unit.. it's brand new... 210 bucks to your door

Thanks

Patrick DeGrosse Jr.

Tom 400 CFI

Step one: Don't listen to Centerforce.

Step two: Continue on your current path. Use the LT1 flywheel, A '93 and up LT1 spec clutch, throw out, fork, and slave. Get the flywheel machined and balanced to match your old flywheel;

https://www.thirdgen.org/techbb2/sho...&highlight=t56

https://www.thirdgen.org/techbb2/sho...&highlight=t56

Granted yours is a bit different than what the folks in those posts were doing, but I think that will only make things easier for you. Acctually, the flywheel MAY be a direct bolt-on for your later model, one piece engine. I'm not sure though, so check the bolt pattern and balance against your original flex plate/flywheel.

MrDude_1

you can either take the above advice and get a LT1 flywheel machined...



or you can just buy one already made for this app by one of several makers... i think even centerforce makes one



edit: to be honest, im kinda leery of drilling new mounting holes in the LT1 plate, but the people that have done it havent seem to have had any probs.....

Tom 400 CFI

Yep, people like me. It's ~$60 vs ~$300 for an aftermarket one. I like saving my money, personally.

Plus, Like I mentioned above, I don't even think he NEEDS to re-drill. Those threads above were regarding older, two piece rear main seal engines. I posted them though tho show that even worst case scenario, it's cheap, easy and works out great.

Patrick007

Damn... and I was hoping to have a nice 15 lb flywheel. Well Centerforce makes a steel flywheel... "93-97 6 Speed for 2 Piece Main... 153 teeth... 35.5 lbs!....12.835 OD".. and i guess the clutch I would need is their DF039020.. "93-97 5.7 350 LT1 and LT4 Clutch... 1 1/8" - 26 Spline"..... do those parts sound right?

1LE Flywheel for sale! never opened!.. hehe

Say can I use the LT1 clutch master and slave cylinder? Or even the whole pedal assembly from one of these cars? Just curious...

Thanks as always

Patrick DeGrosse Jr.

MrDude_1

he said he had a 2 piece main.

MrDude_1

yes, you can it bolts right in.


matter of fact, if you dont use the 4thgen clutch pedal, and use the 3rdgen one.. it'll work, but the clutch will stick out all high and wierd looking.

Tom 400 CFI

So you're not going to use the LT1 flywheel??

Patrick007

Assuming the centerforce flywheel is lighter I will go with that one. Otherwise I'll just pick up the stock LT1 flywheel and put the appropriate holes in it I guess. But yea I don't know how I feel about modifying stock flywheels like that. Anyone have a weight on the stock LT1 flywheel? The Centerforce one is 35.5 lbs ... considerably heavier than the 15 lb 1LE unit unfortunately. I was hopin for a real light piece but.... o well. As far as this swap goes... I believe the only other conversion parts I need are a bellhousing adapter, SPD (or other) crossmember, and a 4th gen driveshaft am I correct? Thanks boys

Patrick DeGrosse Jr.

1bad91Z

iTrader: (1)

What are you guys talking about?

If the motor is internally balanced, he does not need to hack weight off of the LT-1 flywheel or weight match it to anything.

You DO NOT have to drill any holes in it to get it to bolt up. My brand new stock LT-1 flywheel bolted right up.

My THIRDGEN clutch pedal does not stick up any higher than my friends bone stock 92 1-LE five speed clutch pedal. In fact, my clutch pedal came out of a 92 v6 5-speed thirdgen. So, if you've seen a clutch pedal stick out and look "all wierd", then something is wrong.

Good luck and dont forget to put a roller pilot bearing in the back of the crank for the input shaft of your T-56.

Tom 400 CFI

He has to balance AND drill the flywheel from an LT1 because has:

Internally balanced, 2 piece rear 350.

And the LT1 is:
Externally balanced (at teh rear) 2 piece rear.

So the LT1 flange is smaller, and it doesn't have the counterweight cast into the cran as the 2 piece rear engine does. Thus, GM adds weight to the Flywheel to compensate. When placing that flywheel on a 2 piece crank, the flange must be machined, new bolt holes drilled, and the flywheel must be neutral balanced. Just like in the links I posted above.

Patrick007, like an idiot, I mis-read your first post so I was off on several points. I saw you had an 89, but missed that your putting in a 2 piece 350. So the link and what I did DOES apply.

Also I rear 1LE, but "saw" LT1. So yes you do need to sell that flywheel; it won't work. GOOD NEWS though.... the LT1 flywheel weighs 16 lbs. So no big sacrifice there.

And as I stated in one of the links above, I did drag race my car hard with that flywheel, and never had a prob. I pulled it years ago, and gave the T-56, clutch, flywheel -the works to a friend, and now that very same flywheel resideds in a 400 hp camaro. Still no probs. And we did inspect the flange when we pulled it out of my car, and it was fine.

Patrick007

Do you have a GM part # for the LT1 flywheel? Also, is putting the new holes into the flywheel and opening up the ID the only necessary machining to it and can I do this myself? (you guys really confused the hell outta me as far as that goes and I do have access to mills and other machining equipment but idk if I need a special jig or something to get the bolt pattern right). What should the ID be on a 2 piece flywheel? I can machine that part of it myself if I have the correct numbers...Thanks a bunch.

And if anyone has an LT1 flywheel for sale with said holes already machined... let me know!

Patrick DeGrosse Jr.

1bad91Z

iTrader: (1)

I guess I missed that. I have a 1 piece 350 and everything bolted right up.

MrDude_1

you can use the stock LT1 bellhousing. no adapter needed..

you need a aftermarket crossmember.

the 4thgen and 3rdgen driveshafts are the same length.. you can use either one.... the preffered ones are either the 1LE alum or the LS1 alum ones..... with how much you want a lighter flywheel, you might want to look into thoes alum driveshafts...




as for the clutch thing, ive seen it first hand on 2 3rdgens where they used the stock T5 pedals and the T56 master cyl.... the diff is only about a inch to a inch and a half, but if you're looking at it, it looks wierd..... doesnt effect driving though.
if you poke around you'll find a few other people noticed it... some people probly have it and dont even notice....

MrDude_1

yup.

straight swap for a 1 piece rear main.

1bad91Z

iTrader: (1)

What would you have to do with the flywheel if your putting it on an externally balanced 2 piece 400 SBC ?

Anyone?

Tom 400 CFI

Patrick007, I don't know what your expirience in machining-wise, but when I had the work doen to my flywheel, it was only $60 or $70 dollars. Even if I had the proper machining tools jigs, and balancing machinery, I would still take it to a career machinist, because of how critical the dimentions, balance, etc are, and the very cheap price of having the work done. JMO.

You can save money on the crossmember by fabbing one. I did just that, and it worked beautifully. As a matter of fact, that same x memeber now resideds in the same 400 horse Camaro as my old flywheel. I would save the dollars there, because that is relatively easy to do, and spend the money on the flywheel.

I agree w/ Mr. Dude about the clutch. I used the LT1 master and slave, and my clutch pedal was a tad high. It didn't bother me, nor did it affect the operation of the clutch. You could simply shorten the push rod if it was an annoyance.

If you are confused about the flywheel, ask specific questions and I'll answer them. But all you need is a two piece RMS flyweel to use as a template. The 1LE flywheel you bought would work as a template for whom ever does the machining, before you sell it.

Tom 400 CFI

If you read the links I posted above, you will see that I did just that... on a 400. Please check the links.

You use 400 flex plate or flywheel as a template for bolt pattern, flange ID, AND for balance. The Machine shop REMOVES metal opposite the side that NEEDS the weight added, creating the same over all effect.

The other option is to neutral balance the LT1 Flywheel, and use one of those cheesy balance plates from Summit that sandwiches between the flywheel and crank...
http://store.summitracing.com/produc...earchtype=ecat

MrDude_1

2 choices.

do like my uncle had to a couple years ago, and spend $$$ on a totally custom flywheel..


or buy one of the newer aftermarket ones ment for it.... i think centerforce makes one of thoes too


im going to have to buy one eventually for the new 400..





edit:

theres also the route Tom mentioned as i was typing this.... ive never considered it a solution for me before though.

MrDude_1

just thought id mention... NOPI (yea that ***** company) makes a T56 flywheel for the 400...

$240!


still a hell of alot cheaper then everyone else... and you may be able to find one cheaper from somplace else.

LilJayV10

iTrader: (5)

It's late and I probably missed something, but how in the hell can a LT1 flywheel bolt up to an older 2 piece RMS block, it's......ahhh hell never mind

Accck I need to go to bed

Tom 400 CFI

That is clearly outlined much earlier in this thread. Go back and read the thread (hint: my posts) and how to get an LT1 flywheel on a two piece RMS crank is clearly covered.

-Tom

pasky

Its my understanding you can't use fourth gen pedals because the clutch pedal is offset about 1/2 an inch.

MrDude_1

you can.

they bolt right up.


and the pedals are even too... you dont get the 3rdgen pedal rise.

85_sc

There is a guy over on www.camaroz28.com forums that is selling a t56 conversion for a thirdgen camaro with tranny and the flywheel to bolt to a 2 piece main seal block. He also has all the hydraulics/pedals, a arlington motorsports clutch, and a spoohn tranny mount. If i were you i would pick that up. Here is the link to the thread I think it's a great deal. http://web.camaross.com/forums/showt...&highlight=t56
As far as a clutch if you already have a transmission i would go with the autozone or advanced auto clutch which is a lt4pp with a higher perfomance disk guys are using this and they're putting out about 370 rwhp. Check www.camaroz28.com for more info on this setup. Plus if it breaks you get a free replacement.
-Scott
P.S. He'll go cheaper than what he has it listed for.

moore82nd

I have a complete kit for a 56 trannsmission swap if your intersted email me at moore82nd@hotmail.com comes with a great condition t56

LilJayV10

iTrader: (5)

Will do.

914Mula

Can you use a Borg and Beck style pressure plate and any 11 x 1/8 x 26 spline clutch? When I was looking through the hays catolog at work there were no LT1 specific clutches. So I was considering ordering the above.

85_sc

No you can't use that style of clutch unless you use a aftermarket t56 or a ls1 t56 with the mcleod mod bellhousing. For the lt1 t56's you have to use a pull style clutch almost all of the preassure plates are the same. Spec claims to have the same cover but different internals that give 450 psi more clamping force. You can use their disk with the stock lt1 pp I just got a quote on a disk and it was $179. I'm not sure if I'm going to go with that disk or the high rpm Mcleod disk. Slp also sells a ligtened pp with 30% more clamping force which might just be a lt4 pp(possibly the same as a spec) instead of a lt1? Correct me if I'm wrong.
-Scott