i paln on putting a manual 6 speed into my next IROC. Which tranny is better. do both of them bolt in with the same modifacation or do you have to do different things to get them to fit.

thanks

 

I have the Tremec T56 Bought it new, expensive but worth every *** damn penny

 

I did a little research on this myself. I found that a ZF has a center distance of 95mm(greater the distance the bigger the gears the stronger the tranny). All T-56's have 85mm, aftermarket and production. Now the torque rating that I found are:

1)aftermarket T-56 = 400ft/lbs (not positive, tring to find it in writing)
2)production T-56 = 450ft/lbs (I am positive)
3)ZF-6 Speed =450ft/lbs (I am positive)

I am personally going to get the aftermarket T-56 for ease of installation and I don't think 50lb/ft will make a big difference.

Now the torque ratings are right.

 

The ZF-6 Speed tranny is bad ***. They are built in Germany andare the strongest production trannys built. They put these in the Z-R1 Corvette with some power. These trannys will take all the abuse you can give it.

 

I put in an aftermarket t-56 in a friends car. Wasn't too difficult. If you call liberty transmission, you can get one for about 1900 plus shipping. You'll need a crossmember and driveshaft shortening of about 2'', and probably a pro 5.0 shifter. You'll also need a hacksaw to cut off one of the gratuitous aluminum mounting tabs. E-mail me if you have more questions. If you are looking for torque capacity, look at the Tremec TKO.

 

I am currenlty running a ZF in my 67 short bed Chevy. Because of the 3.55 gears and tall truck tires, I never use 6 th gear. Other than that, I'm totally happy with it. I've decided to swap it out this season for a TH400 and a Gear Vendors gear splitter.

The ZF is now for SALE! I have put 2K on the tranny and it was removed from a Vette that had 8K, so it is a real low milage unit!It has an Tilton aluminum flywheel, dual disc clutch, McLeod accordian throw-out bearing, slave cyl. w/ braided SS lines...everything for $2000!

Anyone looking to put this in a 3rd Gen may want to look at some of the magazine articles about the old Firehawks that ran this tranny.

 

The ZF is big and heavy, and if it breaks,well........ bend over. It is however very smooth and probably won't break. If you are really interested in the swap look up ZBRA. He used to hang out here but I allways see him posting at http://www.corvetteforum.com now. He's a pretty cool guy and would probably be willing to give you some advice on the swap. You could probably buy his ZF6 equipped Z28 for the price the swap would cost.

 

what year is his Z-28?

 

Good choices! I like Tremec and BW T5 and T56. Go with what your budget allows. Most guys never get the full use of the T56, and I hope those of you who got it get to flaunt it!

 

i dont really have a budget right now. i am in the market for an 87-90 IROC-Z or 91-92 Z28 with a manual and tpi to replace my IROC that i ran into a light pole . so i would like to possibly buy one with a 6 speed already installed so i can concentrait on fixing the rest of the car up. but i dont have a lot of money saved up right now so i am looking at different options. never hurts to look around.

 

It's a '91. I think he's asking around $8000 but I could be mistaken. He may have allready sold it.

 

wow that is a nice car but 8000 is a little out of my price range.