i was doing research and found that in 1992 pontiac firehawks came equiped with corvette ZF-6speeds and i found a ZF- transmission and was wondering if someones has tackled this issue before and what parts would i need or if i would have to custom fabricate sum parts to make them fit or problems encountered when doing this swap well if u guys no let me know

 

Won't fit the car.

You need the right bell housing; no chance without that (unless you are wiling to do some MAJOR hacking on the car). There are very few of those in existence. When I sa "very few", I'm talking like ... less than 100. Your odds of getting hit by lightning tomorrow morning on your way to the coffeepot are probably higher than your odds of finding one of them.

Then, the trans isn't a particularly great unit, to begin with. The T-56 is a FAR superior product. And FAR easier to install.

Not the best idea in the world. Too much maze, not enough cheese, easier to run a MUCH shorter maze and get ALOT more cheese by going some other way.

 

Ther ZF6 (S6-40) is a superior transmission to the T56, especially a stronger black tag. IT's stronger and shifts much smoother. The bellhousing you need is an aluminum one, most are magnesium. Then you need to modify it to move the slave cylinder. The CAGS solenoid is a major problem too, it sticks out the side of the very bulky case

 

This is subjective. The 95mm centerline distance of the ZF6 makes for a stronger gearset over the 85mm T56, but the Zf gears are thinner and the synchronizers are overly complex. Comparing apples-to-apples, the two are probably a push in stock form.. The aftermarket and OEMs (here in the US) has kept updating the T56 and it can be built way beyond the capability of the ZF6. Stock replacement parts for the ZF (again, here in the US) are 2-3x higher than the T56 also.

 

QTP offers a scattershield that will mate the two. Light and strong, not cheap.
What are your feet worth though.
imo the ZF6 is damn near impossible to break and can take MAJOR abuse.
Stupid expensive to have repaired too. T56 shifts smoother imo but as said will cost a little to upgrade its not like they are weaklings though they arent.

Cost wise youre ahead of the game to use the T56. Gearing is about the same and parts are much more common.

 

Mike, what's your take on the synchronizers? The ZF synchro used spring loaded steel ball indexing of neutral all along; the TR-6060 started using that after all those years of stamped steel keys in the T56. I can't recall if they used the multi-level tooth height on the gear or if that was only on the S6-40.

I think it would be fun to further compare the 6060 to the S6-40.

 

yeah looks like the ZF-6 speed is hard to come buy i did a little looking around in the web and they are expensive to buy parts well sumday ill upgrade to the T-56 or sumthing just as good thatnks for all the help

 

Summit offered items back in the day to do that swap, but that was a long time ago when they sold leftover firehawk parts for slp.

 

Call me Lazarus because I'm bringing this one back from the grave! Here's an '86 T/A with a ZF S6-40 behind a 1400hp supercharged big block (good luck getting a t56 to handle that.) http://www.superchevy.com/features/g...m/viewall.html
And they can be purchased at http://www.rsgear.com/products/trans...rmance/zf.aspx
Sorry about the "necromancy" everyone

 

As long as the post has valid information on the topic at hand. Not like a 10 year thread revival for a "lol" post with no pertinent information. Your good

 

Yea I don't want to be one of the guys who enjoy beating a dead horse

 

Too bad articles like that lack detail on trans. mods.

 

Any pictures of the bellhousing under question? Any pictures of the fitmetn?

 

Old post but i have, search "it has begun"

 

Since this thread has been revived again, Hawk's has a couple of complete L98/ZF6 drivetrains available, which means bellhousing too. I've been eyeing them for a while, but only for the ZF and bellhousing, but I doubt Hawk's would sell them without the engine, so might as well put them out here for all to see.

1988 Corvette 5.7L 350 TPI Tuned Port Engine 6-Speed ZF Manual Trans 111K Miles - Hawks Third Generation

1990 Corvette 5.7L 350 TPI Tuned Port Engine 6-Speed ZF Manual Trans 164K Miles - Hawks Third Generation

 

No it's not. Agree that a ZF in a 3rd gen might not be the fastest/easiest/bestest conversion idea....but the ZF6 is probably the STRONGEST TRANS EVER PUT IN A CAR (SEE POST 26 & 27). This is coming from a guy who's had 4 T56's in 4 different cars, and one ZF6 car.

 

I'll add my 2 cents.

I've owned SEVERAL T56 and ZF6 cars. Both black tag and blue tag.

I don't love either, TBH. I think both shift like crap. I've run aftermarket shifters on both.

A stock ZF6 is stronger than a stock T56. But the rollover noise is kinda obnoxious. In a fiberglass C4 it's not terrible, but on a steel thirdgen, and especially with poly mounts, I wonder if it wouldn't amplify the noise. (I've been learning a lot about drivetrain noises the past year).

I still think the T5 is the best shifting transmission ever produced.

I had a TKX for a little while too.

 

The answer in 2025, very soon to be 2026, is to just buy the Magnum F from Tremec with your choice of gear sets, I recommend the closest ratio gear set, but thats me.

 

Probably. Especially for something going on the highway, LS swaps, etc.

 

This is interesting, b/c "Best shifting" and "Shift like crap"....depends on the context/usage. I agree that in general usage/street/casual driving, the T5 is an absolute joy to drive and shift. With a good shifter? the experience is hard to beat. T56 varies widely, depending on the application. In casual driving, the ZF is heavy, clunky, throws are pretty long, the multiple shift boots make it stiff -especially when it's cold. Thus, I agree that in 90+% of all driving, the T5 provides an awesome shifting experience.

OTOH...when it's "go-time" at the drag track, nothing that I've driven can match the shifting performance of the ZF. I've never missed a gear with mine, and every shift every pass is a flat foot affair. When driven in anger, the friction imparted by the shift boots...doesn't matter. It disappears. The long throws give the driver a better mechanical advantage toward the synchros....and the synchros? They're awesome, when used that way; it never "fights back". I've blown many-a-shift at the track with both the T5 and T56 simply b/c in that driving/usage mode, the synchros definitely "fight back" and want to **** block your efforts to shift FAST. They don't want to do it.

^That^ is a rare/limited use case however. It's an important use case (to me), but not a high frequency use case.

 

It's like women, people have difference preferences. The T5 just glides from 1-2, 2-3, 3-4. The ZF6 and T56 feel 'notchy'. The ZF6 kinda feels like the truck transmission that it is. I never blew one up though.

I switched to a TKX last year and tried that for a few months. Not the terrible but not as smooth as the T5. Has a TON of backlash though from the factory. Like way too much.

I'm actually switching the car to automatic. Getting sick of shifting, and I think the computer can shift faster at the track.

 

I agree that it's like women; but for me, it's b/c I LIKE THEM ALL!....for different reasons. And find all of them annoying at times...for different reasons. I'm pulling the ZF from the Kart and putting in a T5. But if I were drag tracking the Kart there's no way in hell I would make that swap!

Agree that an auto is faster at the strip w/todays power levels. Don't care b/c it's not "earned", but TETO.