LT1 Man

Hello, CorvetteForum Buddies!

I would like to know if a T56 6 speed would fit in a C4 corvette to get more gears for more speed


Post from LT1 Man

cv67

plenty of guys have done it if you cant do the ZF which is way stronger still a good upgrade sure they will pipe in

Tom400CFI

It will fit with some fabrication. It won't give "more speed" though. It might give you better fuel economy....what trans do you have now? Your name "LT1 Man" indicates that you have an LT1 which would have a ZF6 -same number of gears, and similar ratios.

streetstylekyle

So I can pop one in my 96 lt1 right? It has the 4L60e right now

Tom400CFI

No.

Since your car is an automatic (which you didn't mention before), it will require quite a lot of custom work. Unless it is a personal "challenge" to accomplish, you'd probably find better value in selling your car and getting a stick shift. You'll end up with a stronger trans, a better shifting trans, a proper fitting trans, and a stronger rear diff too.





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streetstylekyle

Ok maybe not pop right in. But with the necessary parts I could have the benefits of still being able to buy T56 parts whereas I see everyone struggling to get parts for the ZF

c4cruiser

OP: You may be able to find T56 parts easier than ZF parts, but the conversion from an A4 to a manual setup will be both time consuming and expensive. Just finding the necessary parts to convert to a manual setup can be a PITA.

One thing about the LT1 engine and A4 combo is that the gears in the diff are different compared to the ZF trans. Do you know what gear ration your car has now? It will more than likely be a 2.59 or an optional 2.73. Manual trans cars had a 3.54. Even with that difference, 4th gear in the auto trans will be .070 and 6th in the ZF was .50. 6th in the T56 should be close to the ZF. But top speed with the ZF was made in 5th, not 6th.

Tom400CFI

What parts would one need for a ZF6? I've had one for 7 years now....I've put oil in it.

AgentEran

synchro rings can be a pita if you have bad synchros..

ZF is more complicated than the T56, and if you need to rebuild it, its going to cost.

You cant really trust just any shop with a ZF.. There are tear down procedures that if your not holding your mouth open the right way while doing them, you will fck up your tranny.

Tom400CFI

Right...but my point is, where is the burden of "parts"? OP said:
"I could have the benefits of still being able to buy T56 parts whereas I see everyone struggling to get parts for the ZF"

Who is "everyone"? What parts? Neither trans is particularly troublesome (or in need of parts)...and the ZF is even tougher than the T56. I'd say that if you keep decent oil in the thing and keep your clutch working right...you won't ever have a problem or need parts with a ZF6. IOW, there isn't an epidemic of "everyone struggling to get parts" with ZF6's. Not a meaningful reason to pick a T56 over a ZF6, IMO. If you DO need parts, ZFDoc has 'em and RSG has them too. For starters.


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v8vette84

Lots of bad info in this thread.

It's NOT expensive to swap from A4 to 6-Speed. The only real costly item being the trans which should be expected anyways. If you are mechanically inclined at all its not even that hard. I put a T-56 in my C4 and I love it. The ZF being stronger than the T-56 is debatable as I doubt people have tested failure points of both trannys and been able to compare the data accurately. Both the ZF and the T-56 are plenty strong and you won't have to worry about it so forget about it's strength unless you are pushing massive number.... Also the T-56 is FAR more common with the ZF bringing more money so it's easier to find and cheaper. (At least around me but even by numbers built it should be more common everywhere)

You will need an adapter bracket to adapt the C-beam to the tail of the T-56. The one I bought was nicely built and was like $150 of so.

Another issue is the shifter of the ZF sits 2" to the left of the center of the tunnel where the T-56 shifter sits in the center. Solution: Cut your shifter and move it over 2" and it will sit in the correct position. Bam, easy.

v8vette84

This response is nonsense... The idea is IF, IF the tranny ever needs parts they will be harder to find for the ZF. Or at least much pricier. Sure you can get ZF parts but probably not through normal channels, you have to go through specialty dealers/sites. Both trannys are very capable and the (3) T-56's I have bought have all been flawless for years and years.

Bottom line: I wouldn't factor in the strength or longevity of the trans when comparing because both don't seem to have any issues.

Also 7 years is hardly a great gauge for factoring longevity... Just saying.

v8vette84

Although I disagree with how "hard" the job is I do agree you will get the stronger tranny (compared to the 700r4/4L60e anyways), stronger diff and the correct fitting tranny.

There's hardly any custom work to complete a 6-speed swap... I should know, I have done it, and that was even the "wrong" tranny. You only need custom work if you refuse to buy the swap parts others have already labored over to get right like the T-56 to C-beam bracket.

Tom400CFI

That is literally, what I had just said in the above post. Lets have a look...shall we?
Wow...that is very similar claims, if you ask me! Very similar.



The rest of my "nonsense" response? Lets review so we have our context correct, because believe it or not, context is important. The challenge of getting parts. The OP said: "I see everyone struggling to get parts for the ZF"

Where is this happening? Who is the "everyone" who is struggling?? Especially with a trans that "don't seem to have any issues"...right?
So *I* said; I've had mine for 7 years and put oil in it...to quickly give an example of "how many parts" one guy has needed for his ZF, in the last 7 years....not many.

Lets review some other context; the work involved with a swap. The OP said: "So I can pop one in my 96 lt1 right?"
Would you agree with ^that^? You can just "pop one in"? No, you can't and to tell a poster that you can would be incredibly misleading. No one said it was hard or excessively expensive (your words). All that was posted was the requirements (fab work) and benefits of the stick shift car (already done, better trans, better rear, and more).

If you're going to pitch my posts as "nonsense"...then say nearly verbatim, what I just said....well, good luck with that.


Lastly: Durability. Look at what TPI421VETTE is doing with his ZF6 (and how many parts he's needed for it, too!). Show me a STOCK T56 that will do that. Good luck with that, too.

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v8vette84

You sure can't stand being wrong can you? Its funny how you always bend what you say to accommodate you being right. You must truly believe you are smarted than everyone else. Anyways...

You sure seemed to be implying that worrying about getting parts for the ZF is not worth the time because YOUR car that you have owned for 7 years has not broke. That is nonsense. Plus I agree that breaking the ZF is unlikely BUT that was not the discussion. The discussion was on getting parts and it's sure not as easy as getting parts for a T-56.

The T-56 is a very strong tranny, sorry that your a ZF fanboy and can't accept that an "F-body tranny" is just as good as your Corvette ZF tranny... Just because TPI421vette hasn't broke his yet doesn't mean its strong enough to handle the continued abuse. Only time will tell. Doing a 5 min search brought up plenty of 9 sec T-56 cars but I couldn't confirm that it was on the factory input shaft. I know one claim was for mid 10's on the bone stock tranny. Sure not as fast as TPI421vette but what kind of HP does his car make? A 200hp car can be fast as hell where an axle twisting, tranny smashing 700hp monster could be slow. Again not a good comparison of strength.. You of all people should know that. Hell there are factory 7" 10-bolt F-body rears running 10's for a bit but don't last.

Also YOU said "it will require quite a lot of custom work" that implies that it will be a lot of work as custom parts are not always easy to fab up. Not sure how that could be interpreted otherwise...

Nobody said you could just pop one in but telling someone its lots of custom work is misleading also.



Have you personally swapped a T-56 into a C4? If not I would assume you should not make statements based on 0 experience. You sure seem to know everything about everything...

Tom400CFI

What did I "bend"? I think that I laid out the facts quite clearly, then I gave my option about the most sensible route.. Then you practically quoted me...but called my posts "nonsense"!


Absolutely not. How is an example of longevity, nonsense? While I admit that it's proof of nothing...it's most certainly an example...is it not? I implied no such thing. It was just one example. What I DID "imply" -actually, I said it straight up; was "where are all the people "struggling" to get ZF parts? Where? That is what I said, and it was no implication; it was a direct question to make the point that there is not epidemic for getting ZF parts. I even posted to places where you can get 'em.



That wasn't my perception of the conversation at all. Lets review what the OP said...again:
"I see everyone struggling to get parts for the ZF"
To ME...that seems like a conversation that there is some "epidemic" (my words) in getting ZF parts. Who is the "everyone"? Where? What parts? In reality, "everyone" isn't struggling to get ZF parts b/c 1. ZF's don't break much...and 2. You CAN get parts if you try. FYI, I had a hard time finding parts for my recent T56 rebuild.


Well....That is QUITE some ASSumptions that you've made there. Shall I do the same? I'm sorry that you're a poor, insecure little F-Body/boy and wish you could have a REAL ZF/Vette! Of course, that was sarcasm, to show you what it's like if *I* take ASSumptions to the point that you just did. Back to REALITY...I've had T56's. 4 of them. 2 in F-bodies, one in my C6 and one in our CTS-V (which I just rebuilt, BTW b/c it blew at ~130k miles). BOOM! There goes your ASSumptions about me and T56's. Nice try though.


He's put in his time. It's seen continued abuse. Do your home work.


Do your own homework. READ Trapping 144ish? I'm going to say...700 hp. 1.3 60's. Getting hit by a McLeod dual disk clutch. 5000 RPM dumps, 420+ cubes and hitting it w/nitrous (at the launch!). As he says; "I've been abusing this trans for 20 years, and it still works!"

Where are the T56's that will do that, stock?? Where?



Yes you are right; my SAYING "it will require quite a lot of custom work"....really does imply that it will be a lot of work! Excellent detective work! Actually, that wasn't an implication. It was saying it...straight up! Look up the word "implies" please. But, again, there is the issue of context. The guys said "pop one in". Can you just "pop one in"? I asked you that above....where is your answer? SO...w/in the CONTEXT of the OP thinking that you can just "pop one in", there IS quite a lot of custom work...no "implication" there at all. I said it straight up, and meant it -in that context. Lets examine the work necessary;
* C beam adaptor
* cutting a hole for the master
*clutch/TOB/FW solution
*cutting a hole in tunnel for shifter
*shifter boot solution
*wiring/ECM changes from auto > Stick

....OT, but after that, you've got a home made, 6 speed car with a D36 and 2.xx gears.

But MAYBE the guy is a great mechanic/fabricator and can whip up the pieces lickity-split. You think that's the case so to HIM, he could just "pop one in"? The same guy that wants "more gears for speed"? You think "that guy" has got the skills to "just pop one in"? Context.



Somebody certainly DID say that. I even quoted it above. Should I again? W/in the CONTEXT of a guy thinking you can "just pop one in"...compared to THAT perspective...it IS "a lot of custom work", or how ever I originally said it. In other words...it ain't no "direct bolt in". You ain't gonna...."just pop one in".





I'll admit it, I don't know everything...but I know more than you. I'll be honest that I've not swapped a T56 into a 'Vette...but I have swapped numerous trans's (T56's included) into GM vehicles -even converting auto's to T56's. Have you swapped a T56 into an LT1 'Vette and done the associated ECM/harness changes? If you have...why don't you make a very specific list that outlines the requirements to help the OP...rather than nit fuking picking the nuances of my posts? How about that?

corvetteracer72

These guys seem to have a "kit" made for 84 to 88 vette.

Check out the link - might find some info on the subject.

https://shiftsst.com/articles/cat/ge...1988-corvette/

73n95

wow, there's 10 minutes wasted of my life I will never get back!

streetstylekyle

Guys I'm not even the op here haha. I just wanted to know if I could buy the cheaper easier to find (based on what I've seen) t56 is compatible to the lt1 in my auto car. Considering I don't have the money for the 1996 lt4 already manual corvette I wanted to make my own from a 96 lt1. Built not bought foos. Peace

Tom400CFI

It can be done. It's been done (in a C4, not sure about the LT1) Make a complete plan ahead of time so you're aware of scope of the project.

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