Tootie Pang

iTrader: (2)

Stock LB9, 89 IROC Vert.

I hoping to just sum it up for comparison. I'm leaning towards a T-5 to honor my KISS philosophy but if the T-56 conversion isn't much different, I maybe should do that. I

1. Cost $800-$1200 for the T-5 vs $?? for the T-56
2. First Time Hours: T-5 one weekend, T-56 ?
3. T5 is a pretty straight swap, T-56?
   1. Cable speedo vs ?
   2. Adapter bellhousing?
   3. Clutch Master/Slave cylinder to Pedals for T-56
   4. Auto driveshaft reuseable?
4. Strength for
   1. A stock engine ? T-5 OK, T-56 Unbreakable
   2. A 450 HP engine ? T-5 treat it gently?, T-56 just fine?

Edsiroc

iTrader: (2)

1. Cost $800-$1200 for the T-5 vs $?? The T-56 – would not recommend you to buy a t56 on CL or offerup unless it’s a trusted seller, but a used t56 is usually over $1k around here in Los Angeles and you still need to buy the crossmember, clutch, flywheel, hydraulics, which can easily be another $4-500. I used all stock t56 parts ordered from rockauto.
2. First Time Hours: T-5 one weekend, T-56 – possibly another weekend from experience with my car it took my uncle and myself one day to remove the t5 and install the t56. Would have been a little faster if I didn’t have to go to the auto parts store to look for the flywheel bolts. (This is just taking off one transmission and putting in the other does not include fixing the odometer and reverse light switch.)
3. T5 is a pretty straight swap, T-56?

1. Don’t think there is another option but don’t quote me on that but for the t56 you can buy the Dakota converter for electronic t56 signal to cable speedo. https://www.summitracing.com/parts/d...yABEgJHz_D_BwE

1. Not sure what you mean by adapter bellhousing but the t56 bell housing from an lt1 fits with no mods and v8 t5 that came off my car bolted into my uncles L98. I believe the v6 t5 is different.

I bought my hydraulics for the lt1 t56 from rockauto and it came loaded to just bolt on to the car with no adjustments. (unless you are using t5 pedals adjustment is needed for the clutch rod)

4. Auto driveshaft reusable? Yes, the auto driveshaft can be reused with the lt1 t56.

5. Other notes from experience: do not do it by yourself and be careful with the crossmemeber bolts, the threads seems pretty weak. Might be a good time to change the rear main seal unless you have plans to swap the motor. Can’t think of anything else at the moment.

1. Strength for: Cant say much here I swapped out the t5 for a t56 with the stock LB9 and 3.42 rear and if felt great! Even my uncle liked the way it felt and handled. Swapped out the motor to a 383 with t56 but have not finished putting the car together.

Let me know if you need any more info, this was all from experience from my 89 camaro with LB9 and originally a t5 and my uncles 88 L98 700r4.

jmd

iTrader: (4)

Get the gearing right. A 3.42 rear and 2.66 first gear T56 aren't fun with a 305. A 2.95 first gear trans. works well. A T5 setup can be budget friendly, and sellable when you do an engine change later, if you have good parts.

daferris

iTrader: (8)

I did this for my T56 swap for the cable speedo...
http://t56cablespeedometer.com/t56-c...ve-conversion/
It's essentally the same cost as the dakota box and I feel better... But that's my .02 cents

Tootie Pang

iTrader: (2)

Thanks All. I'll go T-5. It's a stock LB9 vert made for cruising around SoCal looking for Mollie Ringwald and playing Duran Duran. Nothing more.

How's the Summit Racing Clutch setup? Looks like a good kit.

GeneralDisorder

iTrader: (1)

Why don't you just put in a built 700R4? Have you experienced a properly built 700 with a high stall converter?

GD

Tootie Pang

iTrader: (2)

GD, I haven't. I feel like that would be something more worthwhile on my next motor- whenever that will be. The little stock LB9, I wouldn't imagine, wouldn't do much for a trick 700. Maybe I don't know what I'm missing?

GeneralDisorder

iTrader: (1)

Yeeeeaaahhhh..... you don't. I'm still running the stock LB9 (though not for long - maybe a few more weeks to a month) and with a properly built 700R4 and 3000 stall converter it's a whole different car. Also you have the advantage that if you put in a built 700 you won't need to change it out when you go to a larger engine. The T5 is helpless behind a powerful 350 - heck GM didn't even let them out the door with a *stock* 350 because it would shred the poor thing. And there's nothing you can do to change that. With the 700 you can easily buy a trans that can handle 500+ HP and since you aren't doing a whole bunch of modifications to the car you can spend more on the trans and converter than you would on a T5. The only additional parts I would recommend is a proper trans cooler. You are looking at a trans, converter, and cooler - plus fluid, etc. No pedal assemblies, clutches, flywheels, shift linkage, etc. And only about 6 hours of labor to R&R it. Not multiple days or multiple weekends.

Seriously - you need a ride in a built 700 with a 2200 to 3000 stall converter and proper gears. Even with an LB9 the difference is night and day. My back end comes out when I hit 2nd gear. The only mods I have are headers, full exhaust, and 1.6 rockers. I'm honestly a bit scared by the numbers that my new Vortec should be putting out compared to how the car already acts with the LB9. I'll be more than doubling the HP and the torque will go up at least another 100-150 ft/lbs. I will in all likelihood have to consider how I'm going to get more tire under the back, and if the 9 bolt is going to hold up to it..... IDK.

Really the LB9 makes great torque - nearly 300 ft/lbs at a really low RPM. If you harness that to your advantage - sure the car will still be MEH on the freeway when you punch it - but stop light to stop light cruising in town there's not much difference from what many larger engines produce - properly setup you will be wanting wider tires and trying to figure out how to get it to hook up better. Something I seriously doubt you are doing now.

You want to drop the clutch and get off the line right? Maybe with a little squeal and sometimes a little smoke? The 700 can do that. A stock worn out 700 with a factory converter and terrible final drive won't of course. I feel your pain. I came from there. But that's not how it has to be. And for the performance these cars/engines are capable of the T5 is inadequate. A T56 would be fun but that's a lot more investment in both time and materials. And consider the pricing for USED T56's vs. a built 700 that's essentially a new re-manufactured part. Don't forget all the accessories the T5/56 requires that the 700 does not. The 700 is going to be more economical, and more future proof to engine upgrades, and less of a gamble being rebuilt not used.

I think a 5/6 speed F body is great also. I love a manual trans. But the traffic where you live..... I think it would get old at times. And you can manually shift a properly built 700 also. There are many shifters to choose from. I got a vintage Hurst Quarter-Stick for mine. There's a lot of options.

GD

1MeanZ

iTrader: (9)

Everyone has an opinion.

I think 700R4s are terrible no matter how they are built. I had a worked 700 in my IROC years ago and yes it was better than stock, but still wasn’t what I wanted. These are sporty fun cars people! Why would you ever want a lame *** automatic in a car that is supposed to be a fun engaging experience? What’s the difference between a thirdgen with an automatic trans and a Chevy truck of the same year, NOTHING.

Nearly everyone around here that bashes the T5 has never broken one and are just repeating 30 year old rumors. I’ve built many of them, have 3 of them behind 350s. One was behind a trick flow headed 355, one is behind my dad’s heavily massaged vortec headded 350, one is behind my lame *** L05. My dad’s car has the original trans from 1991 and his engine makes an honest 400hp. We’ve flogged it plenty of times and it’s absolutely fine. I would not recommend dumping the clutch on slicks, but for a street car on street tires, I think a T5 is a great trans.

The Mustang guys have had good luck with their WCT5’s for years, and all we do over here is bash them and tell people to keep their farm truck automatics.

GeneralDisorder

iTrader: (1)

If you compare a properly setup 700 and T5 there is virtually no difference in what they can do. You can manually shift the 700 also. And say what you want about T5 reliability - no T5 can handle what a built 700 can. And given equal power plants the 700 will always be faster in a drag. You simply can't out shift it with a clutch.

So that leaves the T5 out for performance and reliability. That leaves driving preference. I guess some people just need something useless to do with their hands. It's like smoking.

I get it. I have owned hundreds of cars. And driven literally thousands more. I own a performance shop. I get the opportunity to drive all kind of strange and exotic cars - supercharged Vipers (ridiculous ***** extensions btw), Hellcats, Turbo Charged Lotus Elise..... ridiculous stuff.

Trust me - the 700 you already have is the answer.

GD

1MeanZ

iTrader: (9)

No one disputes that a built 700 will take more power.

Its about the driving experience, and no a 700 can’t do all the things a manual trans can do. Manually shifting an auto provides nowhere near the control of a manual trans. I’m shocked you would say that after your claims of working at a shop and driving fast cars. When is the last time you saw a 700R4 successfully used on a road course? When is the last time you heard anyone say “man this 700R4 rocks” when they were blasting the curves.

This isnt about drag racing, this isn’t about which trans can be built to take more power. The OP said this car is a convertible that he wants to cruise around. The difficulty level he is willing to accept is his to decide, and you properly outlined the differences. Are you really going to maintain the position that a 700R4 is more fun to drive in a modestly powered street car?

I’m not even here to trumpet the praise of the T5 even though I think the bad rap is undeserved. I’m just voicing the other side of the story here. I think 700s are terribly boring and ruin a fun driving experience. Great for drag racing, good for big power. Wrong tool for the job if you want a fun and engaging driving experience.

skinny z

This raises a question that I've had for a long time.
For the record, I've spec'd and had rebuilt this most recent 4L60 and it is indeed quite an experience when everything functions as it should. Automatic or manual upshifts/ downshifts right where you would want and expect them. All perfectly in sink with the amount throttle being applied. With the 10" converter and 3.73 gear, it has a lot of snap.

But the question is: Can they run successfully on a road course?
The downshifting concerns me as past experience and a couple of postmortems having indicated than an auto doesn't appreciate it.

1MeanZ

iTrader: (9)

I have direct experience here. Some of the fastest autocross cars I’ve been in were automatics. Loose converter, run the whole track in 2nd gear, seamless 1-2 upshift, easier to put down big power because the converter softens the hit some.

Terrible on a real open road course. Rev-matched downshifts are an absolute must, no way to do that currently with a 700R4. If you don’t downshift into the right gear going into the corner, it will down shift when you accelerate coming off it will upset the car. Modern automatics can work on a road course, farm truck 700s need to stay at the drag strip.

Drew

iTrader: (58)

I would hope no one is pushing an Iroc convertible (OP's car) hard enough on a road course for the 700R4 to be a liability.

It's up to what a person's goals are, what they can find, the budget... It's not easy to find the T5 or the T56, they both have artificially high market values due to perceived limited availability. At this point, neither from a donor car is remotely close to a drop-in and go take out. Person should really plan ahead for the contingency that a Craiglist, Facebook, shady character with a stick under his trench coat, used trans is going to need some repairs, and could potentially be little more than a core.

There's something to be said for taking the stock 700R4, and having it rebuilt. You know what you're starting with, no surprises, no conversion headaches (read the T56 thread and all the related threads about pedals and making clutch masters adjustable for examples), you can upgrade the boost valve and drop in a Corvette servo for a little more kick, or go hog wild, plenty of options that bypass a lot of the pain involved with the six speed swap.

Tootie Pang

iTrader: (2)

All good stuff. I think in my case, this car, for the foreseeable future, is a pleasure ride, not a racer. I had WC T5's in my Mustang 5.0 Fox Bodies and they are tough. Non-WC are weak. I've broken many and rebuilt them. At one point (in the early 90s), the guys at the local trans parts shop in Burbank, "Trans-Action", said to me on my third rebuild parts visit in a year, "What shop are you with" to which I replied "none, I'm doing it myself on my workbench" which got a good laugh. I don't know which ones are in the 91 Z28 Camaros (I think it is a WC, the donor car I am getting it from). FWIW, I've also had a built C6 with a higher stall converter. Fun tire breaking changes too. But IMHO, for pure driving fun, a manual is tough to beat and a T5 swap would be the simplest in my case.

Drew

iTrader: (58)

The Fox body will generally put a lot less abuse on a T5 due to weight, and the propensity to break the tires loose and spin while the heavier weight of a thirdgen with a torque arm and wide sticky tires just torques the case apart. Even the Fox body guys turned to the plethora of 4cyl T5s because they were destroying T5s. It's not that the F-body T5 is weaker, it's that the Fox body stresses the T5 in different ways that the trans can tolerate more readily.

If you have a good thirdgen V8 T5 available, the swap is a lot less involved than the T56. Just keep in mind, the way thirdgen T5s fail, you're not left with much to rebuild. If you're confident that no one has abused it in nearly 30 years, go for it. If you're not sure, just keep it in mind.

You might want to look into how and why T5s break in thirdgens. Maybe you'll get some ideas of what you can look for to identify signs of potential damage, or what not to do, that will help you buy a good donor, and keep it alive.

jmd

iTrader: (4)

The countershaft front bearing retainer/race seal leaking is bad sign #1. If the trans is not whining and is in good service otherwise, rebuilding with a G-force case makes sense. If you have access to pull the maindrive out the front (watch for loose rollers since they will fall right out) or pull it w the trans inverted) before purchase, the condition of the headset gears is a good indicator of condition.

The Non-WC bearings for mainshaft pilot, and countershaft nose were feeble for keeping shafts where they should be. The countershaft got upgraded for the WC. The mainshaft pilot only got upgraded for the Cobra and Ford Motorsports version. T5s can be helped, but the shop's that deeply know them are very interested in selling gearsets that don't resolve design issues.

1MeanZ

iTrader: (9)

Hey JMD do you put the billet rear main shaft bearing retainers in? When you shim the front bearing retainer, what end play do you target?

jmd

iTrader: (4)

I have. Iirc, preload is the end game on that one.

SubjectSigma

1. Cost $800-$1200 for the T-5 vs $?? for the T-56

I bought my T-56 for $400 and was able to get it I. The car for about $1000 maybe a hair less.

1. First Time Hours: T-5 one weekend, T-56 ?

Took me about 2 days to get my T-56 in. There's a sticky on here and it's really easy to follow, the swap is also pretty much the same amount of work as putting a t-5 in.

1. T5 is a pretty straight swap, T-56?
   1. Cable speedo vs ?

Digital but you'll need a 80 digital reader to convert your speedo signal, pretty easy tho

1.  
   1. Adapter bellhousing?

The LT1 uses the same bellhousing pattern and input shaft as a regular 1 ps RMS small block chevy.

1.  
   1. Clutch Master/Slave cylinder to Pedals for T-56

LT1 Camaro pedals mount right up

1.  
   1. Auto driveshaft reuseable?

Yup

1. Strength for
   1. A stock engine ? T-5 OK, T-56 Unbreakable

Heard horror stories about T-5. I give my T-56 a good working and it has had no issues

1.  
   1. A 450 HP engine ? T-5 treat it gently?, T-56 just fine?

HP isn't what breaks transmissions torque is. That being said The T-5 was rated at 300lb-ft where as the later LT1 T-56s were rated at 450lb-ft but I'm fairly certain can handle quite a bit more



Honestly after driving it with an Auto and going to manual I can assure you that manual is really the way theses cars should have been.