What is the strongest manual 6 speed tranny that I can mount to a small block chevy engine and still be able to fit it into a thirdgen? Thanks for any input.

 

My guess would be a T-56 out of a 4th gen or a C5 vette. They have been fit into third gens. Maybe there is something better out there, I am sure that T-56 is your best bet.

 

i was thinking a t-56 also.

 

the c5 transmission is in no way compatible with any other car. its a custom housing built specifically for the vette, and its actually part of the Diff assembly and is mounted in the back. its closer in design to a transaxle than anything else.

also, i believe the gearset and such is a ZF 6 speed design, not the T56.

The viper t56 is an application specific transmission as well. You have to make sure the trans will bolt to your bellhousing.

 

The ZF 6 speed is the strongest, its built in Germany. They can on the LT5 ZR-1 Corvettes. I don't know if they will fit a small block though.

 

Great guys, thanks...anyone know of a strong universal chevy small block 6 speed; other than the notorious T-56 (which is probably what I will end up going with anyways) but none the less... Thanks again!

 

not positive on that, but i do know you can get a ZF 6 speed in the newer pickup trucks so they bolt up to the gen III small block for sure. but its only a matter of an adapter bell housing if it wont bolt where you want it anyways.

 

richmond 6 speed ROD

jericho

maybe G-force

 

Does anybody have a link for any of the above stated trannies?
i.e. G-Force, Jericho, Richmond...Thanks again.

 

Your confusing the two 6 speeds. They are both called "ZF 6-speeds" because they are both 6 speed manual transmissions and both built by the ZF Automotive Group based in Germany. However, the transmissions are very different. The Truck version is much larger and had provisions for a PTO (Power Take Off). It is named the S6-650, RPO code: ML6. It has a first gear only suitable for towing heavy loads and the 6th gear ratio is its only overdrive gear. If I'm not mistaken (I might be, it have not had to mess with one in a while) but I think they were only put behind the 8100 Series Vortec engine, which is a "Big Block". I left my "ZF 6-speed" book at work, I'll reference it Monday if there are any more questions about it.

The Corvette version is named the S6-40 and is 95mm between the mainshaft and countershaft centerlines vs the 85mm BW T-56 the F-cars used. It also has 5th and 6th gear as overdrive gears.

 

thanks for clearing that up.....

the zf 6 speed is one of 2 options behind the 8100 vortec, you could either get that, or the allison auto 5-speed.

im pretty sure the zf is an option in all the other GMC trucks as well, i know we could have ordered my dads sierra with one, it has a 6.0 and 4l80E

oh ya, the 6.0 block is an exact casting of the LS1 block...the only difference being that it is cast iron and not aluminum and slightly larger displacement. so the genIII small block thing is correct.

 

I don't think the ZF 6-speed was ever available w/ the 6.0L When the tranny first came out, I'm pretty sure they said it was only available behind the 8100 Vortec. If you got the 6.6L Duramax, it automaticly triggered the Allison LCT1000 5 speed automatic.

As a matter of fact, if you go to www.gmc.com and try and "build" a vehicle, as soon as you click 6.0L Vortec engine, it blocks out the Allison and ZF transmissions, so you can only pick between the 4L80-E or the NV4500.

At any rate, the Y-car ZF 6-speed is stronger than the Borg Warner t-56, but I have no idea if it will bolt up to a SBC or not. If I'm not mistaken, didn' t GM put the 6-speeds behind the LT1?? If thats the case, then it should bolt up.

 

i looked at one on the lot man, dont know what to tell you except that there was on there, and it was plain as day written in the options on the window sticker. a 6.0 with a zf 6 speed.

with the 8.1 the zf and allison are your only option....and i believe you can order the either of those with the duramax as well. this was the summer of 2001, 2002 model year

 

Hmmm, thats interesting. I work at a GMC dealer, but we have NONE on our lot w/ the 6-speed, so I can't go looking to find one like what you saw.

 

the corvette 6-speed is not mounted to the engine, havent you seen one? its mounted to the differential unit in the back of the car.

 

I'll be the first to admit, I'm not "up" on the Y-platform, but notice I said LT1 engine, which means that we are talking about the C4 chassis, which had the tranny bolted to the engine. The Vette, AFAIK, didn't put the tranny in the rear via a "Torque Tube" untill the C5/LS1 debute in '97. Thats one of the features that made the C5 so "revolutionary". And YES I have seen lots of rear mounted C5 trannies.

 

ook man, no problem i just thought you were referencing the lt1 f-car and the c5 vette, not the c4. that makes more sense.

those are still weird though

 

The ZR-1 was a C4, with the ZF6

 

The ZF 6spd was available in the 91-92 Firehawks, so it should bolt up to a small block.

 

Good point.

 

I forgot about that, cool, i'd love to find one!

 

the richmond maybe,

but as for the jerico and g-force, i doubt this guy wants to take out a second mortgage for a tranny.

i wish i could afford one of those

 

me too, but he did say "Strongest"

 

i want to put in a jericho in our new 69 cyclone project. heard those things are really noisey, no synchros and all.

 

true true......hey if you got the money, hammer down.....i would

 

The Richmond 6 speed (5th gear is 1:1) with 2.77 1st & 0.84 6th is rated @ 500 lb-ft, and the Tremec TKO2 5 speed (4th gear is 1:1) is rated @ 525 lb-ft. The T56 tq rating is lower, and uses less resiliant aluminum forks, & 4th is 1:1, with 5th & 6th both as OD ratios.

 

ya my tremec has a 1:1 4th gear and a .68 5th gear overdrive...its very nice on the highway.

there are options though, the .84 is standard.
first gear is 3.27, 2nd is 1.98, 1.2? i forget

 

Tremec TKO 3.27 1.98 1.34 1.00 0.68

FWIW.

-Schultzy

 

The ZF is a super sweet transmission, very strong.

The ZF out of a late 80’s early 90’s 6-speed corvette will bolt right up to a SBC. You will need to make a custom transmission cross member and I believe a custom torque arm mount. You will also have to make a custom center consol because the ZF’s shifter sticks out to the left to far and will hit the side of the stock consol.