Hey everybody! Just wanted to get some feedback on this. But i have an opportunity to get my hands on a T56 and almost everything else needed to do the conversion into my 86 IROC! Price.... 1,300.00 This stuff is coming out of an 96 Trans AM with just over 80,000 miles on it. The only other things that i would have to buy is the crossmember and whatever money it will cost to change over my mechanical speedo to electric. So what do ya think?

 

good deal

 

What rear end are you running? Have you reviewed Porkyzilla's experience with this swap? Be sure you got everything for $1300, maybe ask TKOPerformance at the top of this category what he thinks.

 

$1300 is a pretty decent deal. You'll be looking at around 130-140 for the crossmember, and if it's a 2-piece rear main seal engine you'll need the $pecial flywheel for the swap (runs about $400.) You can also get the tailshaft modified to use the cable sender, or get an electronic->cable converter (the Cable-X from Abbott.)

 

If you can squeeze another $600 you can have a Brand New One.

Jason

 

Hey guys! I picked up all my stuff on sat. I cant wait to get all this stuff put in! :lala:

TheGreatJ- ill be ordering the cross member from Spohn here soon and as far as the fly wheel, im glad i have a 1 piece rear main seal. 400.00 bucks is crazy! but i would buy it if i had to. and on the speedo ill probably use my butt speedo for now.

jrg77- i thought about doing that but from what i checked a brand new T56 was like 2,400.00 and a rebuilt one was line 1,900.00 but maybe i didn't look hard enough :shrug:

rbjones- on the rear im not sure right off the top of my head. so ill have to check the RPO when i get a chance. I think its like a 3.23 or 3.27, its not a posi.

Yesterday i put the 4th gen pedal assembly in. and as everyone else that has done the swap knows, that this can be murder on the back even if you pull the drivers seat out

 

Hmmm, very interesting swap--it's recommended to run at least a 4.10 rear end with a T56 but I see where I could do a T56 with my 3.73's; it would probably do about 1800 rpm at 70 mph in 6th, not too low for a stock motor but a little too low for a mild cam. Good luck.

 

Thanx for the feedback rbjones. But what would my car run like if i did have the gears that i was mentioning? Good or bad??

 

I ran mine for the first year with 2.73's. It was nearly un-driveable. Stock gearing for a T56 car was 3.42, so anything higher than that will work fine. I run 3.70's behind mine and LOVE it, I pull 1600rpm at 60 and get 23mpg on the interstate.....with a 4-barrell 355 and a not-so-mild cam. She'll also chirp 3rd at 50mph.

 

lol I wouldn't say at least a 4:10 gear, knowing they came with 3:42s from the factory.

 

Hey J! when you say "nearly un-driveable" can you specify for me your experience. Thank you in advance!

 

Excessive bogging off-the-line, having to ride the clutch for 30 feet just to keep the car from stalling out, not even being able to use 6th gear without going to jail.......you know, barely driveable.


3.23 might not be too bad, but anything less will be rough. It'll do for a while, but change your gears as soon as possible.

 

anything less then a 3.42 rear, and you start excessivly slipping the clutch to drive.

i drove my car with 2.73s for a month with the T56 after i blew up my other rears... it SUCKED.

 

I am running a set of 3.27's in mine right now and it it just fine. I'm not going to you and say that it is the ideal gear, but it is easily driven. The only thing that sucks, is that in 6th gear, you can NOT just mat the pedal to pass on the highway, you have to dowshift into 4th or 5th. I will be getting a set of 4.10's in my car soon, but if you have a 3.27 you will be able to drive with no problems. I don't have to ride my clutch at all.

 

Alright guys! I have some good news and some bad news. The good news is.......... crap, no good news. The bad news............. well, lets put it this way. Any of you know what RPO GU2 is???? You guessed it.... 2.73 I might just wait to do the swap.

Is it really that bad though? This is the car i drive daily. The majority of my driving is highway. (about a 30 mile drive one way to work.) I would be ok on the highway right? In town driving would be a pain?
If thats the case, i think i can handle not doing this for awhile until i get new gears.

 

Basically, yeah. It's a pain to get moving but after that it's not too bad. As long as it's not 30 miles through stop-and-go traffic, you'll be okay for a couple months. Like I said, I drove mine that way for almost a year (and man did it ever suck.)

 

I ran the T56 with 3.27 and it was a great combo except for take off. I now run 3.73's and feel its a bit short on legs when running good on the street such as long ramps and corners that now require a shift in the middle. Unless you have some big RPM mill in there I think 3.55 would be the perfect all around street gear. My RPM on the highway is just a squeek too high now and the gas mileage suffers considerably over the 3.27's. The flip side to that is at least I can roll on power in 6th without having to gear down which was essential with the 3.27's. So if you split the difference you get the 3.55 and likely the best of both worlds. probably why the Viper and Vette come 3.55 and 3.42 respectively cause it matches in so well with the gearing of the T56.

You will love this trans regardless of the gear you use though. Its butter smooth, whisper quiet, and tough as nails. The only thing that sucks are the clutches and the stock shifter blows goats... er shifts. If you want to save yourself some grief start out with the LT4 pressure plate and choose the disc according to how hard you want to go. There is no low cost option that is worth its weight in scrap when it comes to clutches for these trannies. Good luck

 

Well, looks like you got some good advice there. The 6th gear was originally intended to drop EFI motors into low cruising rpm's to pass emissions requirements--easily done with EFI but sometimes doesn't work well with with a carb. In the barn is a '60 Austin Healey with a solid lifter 11/1 327 first built in 1970. We blew the 3.91 posi's in the 8 3/4" Chrysler rear and put in the original 2.76 pumpkin just to get it back on the road and it ran great with the M21 Muncie. Then a friend of ours asked to use the car as a test mule to develop a T56 bell housing and we got it back with the T56, the 2.76 rear and a 327 made to idle at 1200 rpm--we put it in 6th one time just to say we'd done it--never again. This winter I'll fix the 3.91's and get it back in there--car weighs about 1900 lbs., should idle at 60 mph in 6th.
I first wanted to yank the T56 and put the Muncie back in because it ran so well with the 4 speed; but now I think I'll just get higher speed rated tires, a better roll cage and try that race from Ft. Stockton to Sanderson, Texas in the spring.

 

As always, thank you for your replies. :hail: I do have a little bit of good news though. My other -Z- that is sitting in the garage ( the one under construction ) i found out has a posi in it and has 3.27 and has rear disk to boot!! :lala:
I think ill just swap the entire reared out and call it a day! Come to think of it, this swap will give me a chance to put in the aluminum drive shaft that i got out of a 99' TA. about a mth ago ( the big 3in. one )

Sorry for asking so many questions but what clutches out there would you suggest?

 

Hey 87roc_t56. what advantages would i have with the LT4 pressure plate over the LT1 pressure plate?

 

The LT4 plate is a real nice piece. The best clutch made for the T56 is the Mcleod Street Twin and it still uses the LT4 plate. The street twin uses two discs with solid hubs ( no springs to soften the launch ) which makes it a very serious and very strong clutch but it has a rep for breaking rears and barfing driveshafts like a baby with the flu.

The stock LT1 plate is okay for stock only usage but it is pretty muched maxxed out even for that IMO as the clutches don't last very well if you are planning on honking on it. The pressure plate makes the most difference in performance for these trannies and the LT4 plate is the best. Some guys have had luck with Spec but it seems as if its hit and miss. Just do some searching and you will find all kinds of info on these clutches. Good luck

 

Will do! One more question and ill leave you alone. Would you recommend any other clutches out there that will work with the LT4 pressure plate that are not as abusive on the drive line? Really don't feel like barfin up the aluminum drive shaft ill be putting in behind it.

 

The OEM LT4 disc is okay thats what i am running now... I think Been through so many i can't remember which disc is in there now. Regardless Its the Street twin for me next time without a doubt. Check out Ram and Mcleod online and you can see the different clutch discs available. Once you get into a solid hub design you are into the serious stuff. If you go for Spec ( price is lower ) then be sure to not follow their generous power handling rating chart and get one thats good for double what you need. Good luck

 

...says the guy who evidently never did this swap.

The extra $$ for a "Brand New One" gets you only the transmission.

No bellhousing, pedals, flywheel, hydraulics, fork, and all the fasteners. Take a shot at piecing all these parts together and let us know what you come up with.

 

I ran an LT4 pressure plate w/ McLeod's $100-or-so disc from Thunder Racing for over two years, no complaints here and plenty of abuse heaped on it. No chatter, kinda grabby at first but it got very smooth after it was broken in.

 

Trust me....I did! this is pretty much what i did..... ......

What year T/A or camaro did the LT4 pressure plates come in!

 

every year that someone put a decient clutch in.


i wouldnt reuse a clutch from any car.

 

im not.... the one that i got that came with the tranny looks likes its been in there since 96'

 

my deal haha...yea it gets expensive.....


yea thats a good deal for the swap...since the miles is so low dont worry about it... i have an 90 145 iroc/z28 dash for sale... paid 180 so thats what ill sell it for..

 

The LT4 clutch debuted in the Corvette Gran(d?) Sport in 94 I believe it was. Not sure if other cars got it or not.

 

As far as clutches go, I stuck a SPEC stage 3 in with the trans 3 years ago and am just now having to replace it (trans is in the shed right now in fact.) I had very good luck with it, loved the way it drove, and I'm getting ready to buy another one.

It may be a "hit and miss" thing, but if so I hit it square in the nose. It's been a great clutch.

 

That seems to be the norm for SPEC. You either get a great clutch and love it or a piece of junk and hate it. I have never heard "eh its okay" about them. Its one extreme or the other. Still I have never heard anyone say that the street twin was anything less than incredible. Its pricey but it seems to be the best out there so far.

 

I don't know about the LT4 clutch being a Y-body item, because the LT1 & LT4 Corvettes used a different flywheel & clutch than the LT1 & LT4 F-bodies IIRC.

I would be under the impression that the LT4 pressure plate (edit: that people use with the F-body LT1 T56) was the one used in the 97 LT4 f-bodies.

 

ZF... I knew that. Just tried to recall the first year of LT4 and I think now that I was wrong on that too. 95? Should have had another coffee I guess

 

Don't feel bad. The T56 years are more important. 1996 6 speed vettes and a select few 97 f-bodies had LT4 engines. That's it, as far as production.

 

Isn't that why you start with a stick shift in the first place?

Jason

 

Me neither. I change mine after every time I drive the car. It gets costly, but it's only time and money, right?



bottom line is that clutches can be inspected and the disc is pretty easy to tell if it's readily bad.

BTDT with used clutches and have never been burned (No pun intended.)

 

I might just get with you on that. Ill let ya know.

 

Almost everything is different anyway. The flywheel, bellhousing, clutch hydros, crossmember, hardware, and shifter will NOT interchange from a T5 to a T56. In fact, I believe the only thigns that WILL work are the torque arm, pedals, and console plate. The 700-R4 driveshaft will work, but I believe the T5 piece is the wrong length.

 

the auto and manual cars driveshafts are identical.


only the 3rdgens that had the TH200 and the 4 spd manual use diffrent driveshafts

other then them, they're the same from 82-02

 

I'm thinking 4-speed car then. I knew some of them were too long, I just couldn't remember which.

 

Says the guy who obviously never did this swap. Try bolting T-5 hardware to a T-56 tranny and let us know how that goes. Clutch, flywheel, shifter, hydraulics, bellhousing are all not interchangeable.

 

The hydros will bolt up just fine off-the-car......but when you get the trans in you find that the pressure line is about 10" too short, which means the "hydraulic assembly" as a unit will not work. I found that, with just a touch of filing to the line fittings, the LT1 and 3rd gen slave cylinders are interchangable. In fact I've been running a T5 master and slave with the braided LT1 pressure hose on my T56 for about 3 years now (I like the T5 slave because it has a bleeder valve, the LT1 slave doesn't.) No problems as of yet.

Otherwise, you're exactly right.

 

Hey J! I have a question before i go cutting away at my firewall tonight. How far off can you be with the slave cylinder that is mounted to the firewall before things start going bad? If im off lets say a 1/4 in. either up, down, left, or right. would things still function properly or would i be in deep do do? i have an exact template of the location on the holes that i got from a 3rd gen that originally had a T5 in it. Just looking for worst case scenario.

 

Actually the master cyl is the one on the firewall. The slave is the one down on the trans.

The big concern w/ the master cyl mounting position is to get the shaft straight when it's mounted to the pedal. You don't want the pedal to be pushing the master rod at an angle, it'll accelerate wear in a big way and be spooging hydraulic fluid in short time.

 

Kevin's right...geometry is more important than actual location.

That said, if you're within 1/4-1/2" side to side and prolly 3/4" vertical of the factory position, you should be good. The master cylinder linkage rod will handle a pretty fair angle, but the farther off you are the faster it will wear the seals in the cylinder. It'll be a little more forgiving up/down because that's the way the rod is made to pivot on the pedal end.

 

Thanx for your help kevinc and TheGreatJ! :hail: I was able to get the master cylinder installed this weekend and everything lined up perfect! ( After about 2 hrs of measuring and rechecking everything before i put any kind of hole on my car. )
Hopefully ill be able to put the tranny in by the end of next mth. I still have to buy my cross member and new clutch. I can't wait to finish this swap!!
:lala: