84maroman

I just did a motor swap recent, and have a rebuilt 700 R4. The car is still going to be on the street and I would love to have a T-56. I think it would make driving 50% more fun. But I have heard bad things about the OD on the 700 R4, that's why I almost went to a turbo 400. I am just wondering what people prefer for street/strip use.

ATOMonkey

Very complicated question. On one hand the 700 is a good street tranny because of the super deep 1st gear and the .7 Od make launching hard and cruising at low RPM possible. The 400 is the big daddy of the autos and is completely bulletproof if built right. Then there the issue of the consitency of the auto vs. the weight and efficiency of the manual. I'm a manual man myself. I've heard of a lot of people using 4.10 gears and t56 and still getting over 20 mpg on the highway (.5 od 6th gear). But, I'm also poor and the auto to manual switch was too daunting, so I just had my 700 built to handle 500 ponies which is more than I think my poor short block can handle. Good question, you'll have to deceide what suits you best.

84maroman

Yeah...I am pushing around 440hp or so. Originally I had planned to use this car at the track more than on the street, but now, I am not so worried about the track. Like I said about the 700, it's one of my best friends all around, but like you, I am also pretty poor. I would love to have a 56 but I think because of the fact that I already have a rebuilt 700 in now, I would treat my car according to what I have in it, not build my car according to what I want.

ChevyTough

best tranny no doubt is the Turbo 400... it was introduced into the later 3/4 ton, 1 ton trucks as it will last forever, launching at 6000 it will hold... best tranny. The T-56 breaks all too often, a buddy with a 350 400 hp, broke 7 of his, no kidding... so its not worth it. The 700 R4 is cheap, the OD on it lacks, i would stick with the Turbo 400, best bet, i guarantee!

84maroman

yes, but the 400 was built for a big block. I am running a small block. If anything I would prefer a 350 over a 400. But I prefer a 700R4 over them all. Just personal preference.

Kory-88Iroc 350 tpi

iTrader: (1)

A 400 hp small block broke 7 t56s? Who built them? Was the same one rebuilt seven times by the same person? I have never heard of them being that bad. I guess you can break anything if you try hard enough. There are alot of guys making alot more than 400 hp running t56s though.
Kory

84maroman

Yeah that is true. I have never know anyone running a 400hp small block breaking a t56. I've seen 550hp small blocks break them, but that isn't that often at all. Maybe like the last person said, the tranny was built poorly.

titeride85

no doubt! that must have been the biggest POS t56 ever made. I have talked to people running 500hp thru a t5. and a t56 is supposed to be alot stronger than it. I would go with the t56 if want the driving experience and good durability. if you want the affordability, the 700r4. If you want it to be bulletproof, 400.

logikal6785

perfectly stated =P

Harley83

Why not look into a 4L60E its basically a TH-400 with overdrive. If built properly they can withstand lots of abuse.

Harley83

Im sorry i forgot to mention on the 4L80E you must have a computer in order for it to operate properly and they are a very heavy transmission as well.

TBI305Camaro

Something else to take into consideration...

Oh hedman longtubes were designed to clear 700r4s and TH350s...not T56s or TH400s...

Just a thought.

89formula#1

I have a t-5 in my firebird and i am pushin about 350 horse with my 350 and i just got a ripper shifter and when i rip a gear at like 5500 it grinds but its like so quick and nuthin, but the trannys gonna go. I would love to have an auto so i can go to the track, line lock it with slicks, then launch real nice. Now I think I can get a used 700r4 cheap right? how much can these handle stock?? and do you think me and my dad coudl rebuild one and put a shift kit in it for fairly cheap? cause i am lookin to have a strong trans that can take my engine and have a 3000 stall converter and a ratchet shifter. i need to do this for liek 900 or less, is it possible??

tamatt27

Hey, I want to build a 383, and replace my 700R4 with a T56. I figured that the T56, since it was put behind the LS1, would be able to take a mild 383. Is this correct? Also, what's the current price range for a good T56? Thanks,

MdFormula350

yeah i like the good old 700r4 havent blow one yet, i have gotten close but sold the car..

430T/A

I gotta add my input here, out of my 4 closest friends we all have thirdgens, with the exception of the 93z.

Our cars are all different belive it or not, and we all have different trannys. here are the combos-

I have the beast
85 T/A
436ci buick, TH400 and 3.42 rear end
rpm@65=3000

my Bro
86 T/A
409ci chevy T56 and 3.23s
rpm@65=1200

Friend
86 Iroc
350ci chevy T5 and 3.42s
rpm@65 1800

friend
93 z
LT1, 700r4 and 3.27s
rpm@65 1900

there is alot more at stack then shear force, afterall look at the differences. the 400 is obviously the strongest tranny, but it is handicapped with no overdrive. I seriosly get around 5-8 mpg.
plus the 400 demands alot of low end torque, with such a high first gear at 2.48:1.
The T56 is a blast to drive, but its clutch is so small, with the torquey 409 in its torque peak, the clutch will slip, even though its brand new. granted it is a stock clutch, but it shouldn't slip off the shelf.
The T5is just plain spooky, the clutch hooks, but after a nice beating session, it won't go into first for quite some time. it does grind the gears, and the shifter rail is getting noticably sloppier. by the way, I should mention the 409 ate its t5.
the 700r is a good tranny, but as far as its strength goes, it leaves something to be desired. its overdrive sucks, and its first gear is little to low.

the most expensive tranny was the T56, it ran in at about 2800, due to a 600 dollar core charge. it was a pain in the *** to put in, since it was the Ls1, and it has a Howe bearing instead of a clutch fork and that ****.
swapping to the 400 was easy, with the sphon crossmember. this is the only tranny were a new driveshaft is required, so keep that in mind. also, I already have plans to convert to a 2004r. drving that car on the highway sucks, 75 its buzzing at 3500. I get worse mileage on the highway then street.

after all is said and done, I would recomend a beefed up 700, since it is the easiest and cheapest way to go. unless you plan on building a 700 horse motor, the 400 is not neccesary, and will lag a little of the line. I don't have the lag though, with my 500 ft lbs at 2000. good luck

titeride85

Price for a T-56 seems to be $1200-1500 used. If you are afraid of used, it gets more exspensive. $2800 is awefully high, though. I would also recommend to anyone who is running a performance motor, upgrade your clutch or TC. Whichever you are running, buy the stronger more reliable part. It is well worth the extra bux.

I personally like the T-56. With a 383 it would be fun. I am working on the 406 and looking at 420 hp/450 tq. I forget what the tq rating for it is. I know the T-5 is rated at 330 ft-lbs and the T-56 is rated at a fair amount more, so I would say, as long as you dont completely abuse it, it will handle the 383 quite well.

430T/A

The torque rating for a T56 is 500 lb ft. he got from a place called manstrans.com. what really killed him was the 600 dollar core. the tranny is completly rebiult, and came with the flywheel, clutch and howe bearing. without the core, it was only like 2200 or something. Don't quote me!! the tranny is really sweet though.

86IROCNJ

Plus if your car is an auto, you have to spend the money for the other parts to make the swap work. How strong if the ZF 6-speed, anyone know? Is it basically the same, or no? In the future i would like to have a manual but not if its going to break on me all of the time. Any suggestions, thanks

daverr

iTrader: (1)

i ran into the same trouble with the t-5 and hedmen long tube.i switched to a th350.i thought the 400 looks very similar to the 350 so why wouldnt it work with the long tubes.

dave

430T/A

the longtubes will definatly fit with the t56, I've seen both and the t56 is way smaller then the 700r, and it willl fit

PETE

iTrader: (1)

The ZF is a different animal. No tourqe arm mount,different tranny mount pad, Gear ratios are similar to the T56 but is stronger. If you break a ZF you are gonna be paying some serious cash to ship it back to Germany to get it fixed(nobody is authorized to fix them in the states). The 4l80 is the big daddy of all OD tranny's. With a 2.75 first gear the tourqe rating is quite a bit higher than the 700r4 or 4l60E(same tranny). The OD is a .75 A little bigger than the 4l60E. I've seen published ratinds of 700ft/lbs. for the 4l80E. But for a new one I think it's like $4000. The 700 could be built up with a better drum,12 vane pump,billet servo, and kevlar clutches fo a fraction of what you'll spend for the t-56 or 4l80E.

Just my.02!


You could also go with a 200 out of the 85-86 Monte SS. It has the chevy bolt pattern and can take a lot of abuse if built right plus it has a .67 OD.

dunerida82

Is the turbo 400 an auto tranny only, or manual too?

PETE

iTrader: (1)

It is an auto trans. However before the birth of lencos and libertys racers were adapting the th400 to a bell housing that way you could launch at whatever rpm you wanted then let the auto take over. Wasn't a good choice as reliability goes, but they made it work. It required cutting of the mounting pad and welding a new pad to mate up to a manual bellhousing.

Deimos140

If you actually look at the gearing of the transmission the TH400. You can change first gear to a nice 3.0 or 2.72 and leave third gear at 1.0 or opt for .9 or .7. So basically you could have the best of all worlds.

PETE

iTrader: (1)

Your forgetting something!










By going to a larger first gear the gear drop to second will constrict the tourqe band and possibly hurt your performance. As for going to a .9 or .7 in 4th if you drive it on the street or highway you have to factor in the heat(killer of all autos.....

Deimos140

Man, first the steeper first gear of the TH400 wouldn't be as big as the drop going first to second wouldn't be as bad as going from the 3.06 first to second in the 700R4. Second changing to a .9 or .7 wouldn't increase heat that much. It is a ratio between the driven and driving gear. You need to tear apart a tranny and look at it bud. Plus if he is doing any sort of high stall (which I imagine he will) he better have a tranny cooler or he's gonna cook and spit fluid.

PETE

iTrader: (1)

OK