TKO 500 or T56 6 speed tranny? Help me decide

astronut1885

Founding Member
Jan 31, 2002
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Assonet, MA
Hey guys. I've been toying with the idea of getting a blower, but my stock T-5 is really beat up, and won't last too much longer. I want to get a Tremec, but I don't know which. I can get a TKO500 into my car for around 2,000.00, or I can get a T56 6 speed into the car for 2,500.00. The plan is to have a supercharged 331 stroker planting 500-600 horsepower into the car within 4 years, so I want a tranny that can take the punishment. The idea of a 6 speed appeals to me, expecially with the closer ratios and all the highway driving I do. I know the 56 can take a beating, because they put it in the '00 Cobra R, the '03/'04 Cobra, and the V10 Viper. There's guys running 10s on the T56 with Cobras. I also know the TKO500 is a badass tranny too, so I want to know what would be best for me to get.
 
I called D&D performance, they sell both. They said the T56 is stronger, and is an all around better transmission. It also uses the stock clutch, which is good since I have a 3 month old FRPP H/D clutch in there. I think that's what I am going to go with. Plus, the idea of a 6 speed is just so badass. How hard is it to install it? I've done T-5s and a clutch job with a friend, and it was pretty straight forward. It comes with the bellhousing for a 5.0, so I assume it's a pretty straight bolt up job. Anyone know?
 
The 6spd is overated IMO and costs too much for no real big benefit. The 6th gear isnt much 'lower' then the 5th in a tremec. The G-force syncronized tranny has the lowest 5th gear, .59. I'd do a 26 spline tko500 or a G-force T5.
 
Yeah, there is no real overdrive benefit, and it seems the gearing ratios are set up for a really high power car. With a setup like the 56 has, my car would be sluggish in the lower gears, even with my 3.73s and close to 300 RWHP. I plan on lots of power later though, so I don't know what to do.
 
i too am in the same dilemma, only non supercharged...........im not getting a t-56 tho i can tell you that right now.


hell i wouldent even consider it if it wasnt for the fact of there isnt a good shop that will beef up a t-5 within 500 miles of me.

im probably gonna go with the tk-600, just so i dont have to worry about it.
 
Well, I called D&D again. I spoke to Don Walsh Sr., who's son Don Jr. races NMRA mustangs (and does quite well). Don Sr. is a former NMRA racer in Hot Street competition. He broke it all down for me, gear ratios, options, etc. and here's what we came up with: TKO500 with 26 spline input shaft, 26 spline FRPP H/D clutch disc, Slip yoke for my FRPP aluminum d/s, and a custom cross member all shipped to my door for 2100.00. He said the crossmember makes the install look alot better, and he recommended it. The guy was very honest, and for the extra 100.00 it's worth it to me to do it right. He said the T56 is not going to match up with my setup well, and that the TKO500 was the way to go. It's more than strong enough for my car, shifts well, and is top notch. I guess the question is answered. Now to get the $ and order.
 
I'm just getting an aluminum bellhousing, not the steel scattershield, but that's included in the above price. I forgot to list it.
Oh yeah, now it looks like I am getting the tranny and a blower in September. Ohh Yeeeeeeahhhhhhh!
 
IMO it depends on which T56 your talking about. With the prices you quoted above for the t56 I have to assume your not talking about the Viper or you fogot to add the clutch and installation kit in. There's a big difference in a standard T56 and a Viper both in gearing and strength. And the T56 used in 03/04 cobra's ARE NOT the same as used in the Viper and I have heard of 03 cobra owners breaking them.. If your talking the D&D prepped Viper then it's my impression it's still the big dog of them all and the overdrive is crazy. .50 6th. You pay a little more though. You need a different clutch with a 26 spline but that's not a big deal. With my Viper and 3.73's I could do 80mph at about 1800-1850 rpms on the highway. Now a regular T56 I doubt is as strong as the TKO 500-600 as I believe they are only 440 ft lbs torque. If your interested in a 6 spd I wouldn't go through the trouble and not put in a D&D prepped Viper. It's a bada$$ tranny and has been behind 1000 hp cars. And it's my understanding there hasn't been a mechanical failure yet. The jury is still out on the TKO 600's. Time will tell on them as more and more get beat on IMO. And the 550 ft lbs of torque rating of the Viper obviously appears way under rated.

With 600 hp though I think I may give the TKO 500 or 600 a shot with Mcleod steel bell. It would definetly be a lot cheaper and I think better than a Non viper T56. I currently have my Viper in to D&D getting fabbed up to a Steel bell, that with the Twin disc clutch and flywheel kit I have a TON of cash in this tranny set up. But I am shooting for a lot more hp so I planned ahead. Although the Viper is awesome I think with the new line of tko's out they probably aren't worth the much higher cost. If the TKO's live up to there advertisments, may make more sense in that power range.

Either way Don Sr and the guys at D&D will set you straight on your needs and he stands behind his stuff.
 
My car is going to be set up for auto-x and road course handling, so I want something good for that. It's also a street car that sees alot of highway to campus and back daily, so anything that'll keep the RPM down is sweet. Once I have the $ I am going to call them and see what they say.
 
65ShelbyClone said:
A Viper has alot of torque and 6 wide gears wouldnt be that fun with a lesser engine.

4.30 or 4.56 rear gear will compinsate for the Vipers softer gearing if you were planning ahead and buying more tranny than you need, and with a .50 overdrive still be extreamly streetable. 80mph with 4.56 gears and a .50 overdrive would only be about 2300 rpms.
 
I think I am going to get the T56 now. I've done alot of mods to the motor, and when the tranny goes in, so will a supercharger. I layed 258 RWHP down in May right after the motor was done, and it was untuned. I've since added a few other mods, like a full ignition (no real HP there), A/C delete, electric fan, and other small things. I'm guessing right now I am close to 265 now that she's tuned right. When I do the blower, I'm getting a big MAF, injectors, and TB too, because all of that is stock on my car :mad:. I'm going to get the regular 56, not the Viper one, because it's an extra 500.00, and I doubt I'll ever see that power. I've heard of 03 Cobras running 10s on stock T56s. Another bonus is that I get to keep my brand new clutch that was put in a few months ago. The T56 has the same input as a T5. They sell a full kit with a new aluminum driveshaft for the longer T56 and some other stuff, so I can sell my FRPP shaft and get some money back. I'll probably give my T5 to a friend who wants to rebuild it. I'll get a Tri-Ax shifter for it too, because I don't want to destroy it like I have my T5 with overthrowing on my powershifting.
 
astronut1885 said:
I think I am going to get the T56 now. I've done alot of mods to the motor, and when the tranny goes in, so will a supercharger. I layed 258 RWHP down in May right after the motor was done, and it was untuned. I've since added a few other mods, like a full ignition (no real HP there), A/C delete, electric fan, and other small things. I'm guessing right now I am close to 265 now that she's tuned right. When I do the blower, I'm getting a big MAF, injectors, and TB too, because all of that is stock on my car :mad:. I'm going to get the regular 56, not the Viper one, because it's an extra 500.00, and I doubt I'll ever see that power. I've heard of 03 Cobras running 10s on stock T56s. Another bonus is that I get to keep my brand new clutch that was put in a few months ago. The T56 has the same input as a T5. They sell a full kit with a new aluminum driveshaft for the longer T56 and some other stuff, so I can sell my FRPP shaft and get some money back. I'll probably give my T5 to a friend who wants to rebuild it. I'll get a Tri-Ax shifter for it too, because I don't want to destroy it like I have my T5 with overthrowing on my powershifting.

Why bother if your just getting the regular T56? it's my understanding that it's only rated at 440 lb ft. by the time you do 2000 for the tranny and 650 for the installatino kit plus 200 for a shifter, you might as well go with a TKO 500 which is probably going to be stronger and less expensive and I believe comes with shifter and stops from tremec. I think D&D are selling them for around 1500.

Trophyhead. here is a link http://www.ddperformance.com/t56__6_speed transmissions.htm but the D&D prepped Viper seems to be grossly under rated at 550 lb ft
 
Because I probably won't ever make enough power to break the T56, and according to D&D it's very underrated, and this is the normal one we're talking about. I like the close gearing, from what I read it's what I would want for open tracking.