I'm completely replacing the drivetrain in my Iroc (which originally was a 305TPI/700R4) and would like to use a T-56 Manual Transmission. I would like to buy all the transmission components new to know exactly what I'm getting and am faced with the decision of going with an LT1 F-body replacement transmission or an aftermarket T-56. Either way, since my car was an automatic, I still have to buy the appropriate bellhousing/flywheel/clutch setup. As well, I intend to buy a new driveshaft, cross member, torque arm etc since I'm completely rebuilding the car anyhow (so it does not matter to me that the aftermarket T-56 requires a shorter driveshaft/torque arm). With this established, I'm wondering if anyone has some insight as to whether the t-5 'push' style clutch setup emplyed by the aftermarket T-56 has any advantages over the 'pull' style clutch setup I would have to use with the LT1 T-56. Which setup is superior (or shall I say, which is superior in a third gen)?

As for the application, the transmission is going behind a fairly hefty 427 smallblock (using a Motown block--2 piece RMS) that should be producing more than 500ft.lbs. I know this is over the 450ft.lbs. rating for the T-56, but the car will be babied 95% of the time (and only driven on Sundays in the summer anyhow), and will only ever be run on the track in street attire--so no slicks. I'm sure I'll be fine with a typical T-56 and will probably have a performance rebuild done eventually anyways, but are there any companies that sell T-56s with stronger internals for something else to consider?

Any insight/help would be greatly appreciated!

 

g-force makes a kit that makes the t-56 good to 900 ft/lbs, uses parts from a viper t-56 i think, or its referred to as viper spec.

clutch wise, the mcleod twin disk setup is superior for street use

 

True, if you wanna spend that kinda $. A SPEC stage 3 or 3+ can handle that kinda power too. It is a more conventional style too than the twin disk.

 

I have read about the G-force rebuild kits for the T-56, but can you buy a T-56 anywhere with the kit already installed? I guess I could buy a junk LT1 trans and go from there, but that eliminates the possibility of an aftermarket T-56, because I'm sure I won't find one of them used very easily.

As for the twin disk Mcleod clutch, it does look pretty awesome, but it's also available for both the 'push' (aftermarket trans) and 'pull' (LT1 trans) clutch mechanisms. This essentially is the decision I'm trying to make: Do I go with the aftermarket T-56 or the LT1 OEM T-56? Why?

 

I dunno really. I just went with what I could find for a good price really. Whatever set up you go with I am sure u will get used to it and not really care. I just picked up an LT1 style T-56 a week ago. I don't even know anything about this "push" "pull" thing you are talking about. I am just going this route cuz yes they are made to take 450 ft. lbs. I know guys running over 600 TQ though them on the street. If you know anything about engineering, when a part is designed there has to be a safety factor built in. you can't release a part and say it will break at 450 and actaully havr it break there. They are too many small variables that are unforseen. 450 is just a consefvative estamate.

Rebuild it if it blows up.

T-56/bellhousing/hydos/fork and the best part is I got a flywheel that is custom made for a 2 piece rear main seal. All for 1500 bucks. shipped and with less than 50K miles. from a 94 TA.

 

Right now I wish I knew a little less about engineering...probably because I've got a statics mid-term tomorrow...anyhow...

I really don't know anything about this 'push vs. pull' style clutch deal either...I guess that's why I'm asking about it. I'm really not all that worried about blowing a T-56 either, I was just, as a side note, asking if anyone knew what was available...

Mostly I'm looking to hear whether people prefer the stock-ish T-5 clutch setup or the clutch setup with the LT1 T-56. If anyone knows anything about it, I'd be curious to know which setup has a better mechanical advantage, or even which has a nicer clutch feel (although I know the actual clutch disc used has a huge impact on this)...I'd be buying either trans setup new and I'm not concerned with which one's cheaper, but rather, which is better...it's starting to sound like either would be fine.

 

Didn't meen to sound smart about the engineering stuff. I am a student and my dad is a proffessor, we allways toss in a safty factor in class.

Good luck with whatever set up you go with and that test. And if you learn more about the pull-push thing post it here, to fill us all in. Thx.

 

The pull type clutch used in the LT1 set up is, well not the best thing in the world or anything close to it.
Do the aftermarket thing, you won't regret it.
I have done both and can say the aftermarket is the best way.
Clutches made for those operate the best and hold up the best, regardless which one you choose.

 

Sorry dennis, I also didn't mean to be rude with the engineering comment...I'm also an engineering student....funnily enough, my mother is a professor (though not at my univesity) and my father is also an engineer. The Iroc at the moment is a bit of a family project...well, a family supported project at least

Don, I appreciate the input from someone with experience. I remember reading somewhere that the 'pull' type setup for the T-56 leaves something to be desired, but I never really found the reasoning behind it. One might think that newer should equate to better, but then why are we working on third gens at all? I really like the looks of the aftermarket transmissions offered by McCleod and Rockland Standard Gear (since you can get custom gear ratios, the tough 30-spline output mainshaft, tougher 3-4 shift fork, etc...) ...and I found a great article outlining a T-56 swap in Chevy High Performance with a parts list that I think just became my shopping list for the winter.