futureuser

iTrader: (1)

It actually does sound good. I think my tranny is worth at least $800. I'm going to think about this. The only reason reason I like the 4l80e is for the price I got it for, reliability and for the possibility of a future turbo setup. Hmmm...

OldCobraGuy

iTrader: (2)

I think you would be much happier with the T56. It just makes the car a lot more fun...and I know this sounds strange, but it makes the car feel lighter and more responsive. But I'm here to tell you...this swap is going to cost you at least 2 grand. You keep track of all the expenses and tell me if I'm wrong. By the time you buy a clutch worthy of the kind of passes you are trying to make, driveline mods, etc etc, it adds up fast.

hookemdevils22

iTrader: (12)

I completely agree with the T56 route, especially since you have to remove the trans to install a $1000 torque converter anyway. That plus the $800 you get for the 80e and you can get a T56 plus most of the goodies to do the swap. Autos are great on the track, but it gets no better than bangin' gears. That being said, a buddy of mine went from an auto to a 4-speed and, although he said it was worth it, he also said he would never do it again.

Plus... You could dyno it after and finally lend some solid numbers to the 'how much power does a 4L80e suck vs. a manual' debate.

-TheBandit-

iTrader: (1)

I have also been thinking about a T56, but as OldCobraGuy pointed out, the swap will not be free. Im sure the 4L80E will offset the cost a bit, but keep the peripherals in mind: crossemember, pedal assemblies, clutch, clutch hydraulics, driveshaft, hole in the floor, new shifter, ECM flash, etc etc etc. Pulling a tranny and putting a converter in is not that hard, maybe a day's work. Be careful about going too radical with your build. A high stall may seem like a good idea, but around town it may not be as fun as you'd think. Keep in mind stall speed isn't an exact number. How much it "slips" and when it really bites will vary with engine output. When I was selecting a stall for my TH400 in my old smallblock days, I put a call into BTE Torque Converters and spent a great deal of time discussing my car and the different options for overall size, fin angles, anti-ballooning, etc before settling on a recommendation from them. I'd suggest you have a similar conversation with someone that actually knows what they're talking about (i.e., not plain folks like me and you on the Internet). You have a dyno curve, you know your gear ratios, approximate weight, and you know what you want to do with the car so take that great information to an expert and see what they come back with.

Regarding the caltracs, you can build these yourself without too much money invested. I have slide-a-links and they made a huge difference.

bmf5150

I had heard the gear ratio of the 4l80 where not very good that's why I went with the 4l60??

ponjohn

You also need to be mindful of the fact that the rear may not hold up to clutch dumps at 5500rpm.

Figure a scatter shield in to your costs.

Slide-a-links will eventually bend ESPECIALLY with a stick shift car.
I saw pictures of 67 Chevy with a stick and they bent.

futureuser

iTrader: (1)

Wow, thanks for all the feedback. Yes, I think I could free up $16-1800 by not buying a converter and selling my trans. I think I will carefully weigh all the costs before I do anything. If I get a converter, it will be custom so that it stalls at the correct speed for my application.

futureuser

iTrader: (1)

The 4l60 or 700r4 have a nice low first gear, but then you get a huge drop going into second. I think second is the same and third is the same at 1:1 drive. The 80 has the same gearing as a th350 or 400 plus OD. Depends on personal preference and how the car is being used.

tsnow678

iTrader: (3)

I did the math on the additional Items needed for the swap.
Clutch master from NAPA=$100
Clutch Disc, pressure plate, and flywheel LS6 (Z06) GM from Pace=$477
Slave and release bearing GM from Pace=$135
Clutch line from master to slave from Speedway=$55
Remote bleeder for slave from Speedway=$30
This is a list of parts needed for the swap and the grand total comes to $800.
The driveshaft should not need to be modified since the 4L80E is 32 1/2" long to the tail and the T56 is 31.9". The T56 is only .600" shorter. The trans mount will need to be moved forward 3 3/4". You will need a shifter but giving the fact you will buy a used transmission it should come with one. I bought mine used/new for $100 if it doesn't. I am sure the people that tuned your PCM would modify it for a small fee. So if you decide to keep the automatic you will spend an additional $1000. Take the $1000 and find a T56 and sell the auto and use that money to buy the required items for the T56. I figure if GM put the LS6 clutch behind the Z06 with over 500hp than it should be fine for your application. The clutch pedal modification is rather simple and the clutch and brake pedal assembly is $60 from Classic Muscle. The loss of power from the automatic should be around 25-40hp. I know a Powerglide loses 25hp and a TH400 loses around 40hp just to operate them not counting the slippage from the converter. Just because you have a stick doesnt mean you will have to dump it at 5,500rpm's but it sure is nice to have that option!!! Nothing better than ripping through the curves downshifting and nailing it. I loved my 4 speed and hope I enjoy the 6 speed even better. I am a little dissappointed at the clutch pedal force required though. I thought there would be a big difference between the mechanical linkage versus the hydraulic but there is not much if any. I guess since all of my mechanical linkage components were new it was rather free.

Just options man, just options!!!

tsnow678

iTrader: (3)

Three more items needed:

Pilot bearing from Oreillys=$27.00
Flywheel bolts ARP from Summit Racing=$28.00
Pressure plate bolts ARP from Summit Racing=$17.00

bigmandengo

iTrader: (21)

does the 4l80e use a 32 spline slip yoke like the th400? Most t56s are 27 spline.

futureuser

iTrader: (1)

I didn't count the splines and didn't have to since I reused the 4 inch aluminum driveshaft from the van. I can tell you that it is way bigger and beefier than the turbo 350 slip yoke.

futureuser

iTrader: (1)

TSnow:

Awesome infomation and I really appreciate it. I'm going to Canada for a week and will ponder this with some hosers and plenty of beer, eh?

futureuser

iTrader: (1)

I owned a '72 911 with a 915 trans for a while. Every shift had to be deliberate and precise and it was the only car I could heel/toe downshift. If the shift wasn't right the transmission would grind. My understanding is that a stock t56 can handle 1000hp if it is driven this way.

tsnow678

iTrader: (3)

Evidentily the 4L80E is larger with more splines because I used the same slip yoke from the original Powerglide into the TH350 and then into a Saginaw 4 speed, and it also fit the T56. I did upgrade the yoke on the last driveshaft fitment, same splines and diameter but more contact area as it is longer and I used the 1350 joint so it was beefier also. When I was in the driveshaft shop I was looking around and there was this massive yoke laying there and I had to ask what it was and the guy told me it was out of a TH400. The circle track fellas use them for there strength.


Have one for me, eh? Think long, think wrong!!!

tsnow678

iTrader: (3)

The GM version in stock form can withstand 450ft/lbs. I have a friend that had Tick Performance go through his T56 and he is at 900hp to the crank with out a hang up. Its all going to depend on how well you hook. You can upgrade these transmission to the Dodge Viper componenets and really raise the torque capacity. If you go to Tick Performance website and look under services they will explain what is done, how much, and what the torque capacity will be. Its a little costly to have them do it. I had given it some thought on finding another tranny and tear it down and doing the upgrades my self. Two things in my life I want to do before I go is rebuild a T56 and also rebuild an automatic. I usually end up paying someone to do these for me but just to have the knowledge to be able to do it myself would be great.

OldCobraGuy

iTrader: (2)

Crossmember? Will you need that changed? What about exhaust modifications that may need to be done for clearance around a different trans or crossmember? Slip yoke? Pedals? That's a helluva price on a clutch and flywheel by the way. I was figuring twice that for a McLeod or similar. But that one works unless you really want to hammer on the car...then you need to step up. Finally, when is the last time you bought something used and didn't open it up and look inside? I would NEVER do that. And once inside, I can't imagine at least replacing bearings and seals.

I'm not trying to dampen anyone's parade here. I think this is a very worthwhile swap at any price around $2000. But I have done a lot of these over the years. I'm here to tell you it's going to cost you more than you think...but it's still worth every penny of it.

hookemdevils22

iTrader: (12)

I didn't think to put that on the bucket list when I found the piece of snap ring in my 4L80e pan. Though I haven't built a T56, it can't be anywhere near as involved as the 80e was (judging by the Mazda 5-speed I rebuilt in college).

OldCobraGuy, you're not raining on my parade. In fact, I've become VERY interested in finding and building a T56 now. Now I just need to decide between that and the Vintage Air system...

-TheBandit-

iTrader: (1)

Who/what is "Classic Muscle"? I failed to find it with Google.

ponjohn

If you go to the track and powershift that at 6500 rpm and the clutch comes apart you're going to wish you had a scattershield. In fact you may be wishing that your foot was still attached.

Don't skimp on the bellhousing.