6 Speed swap

2001GT281

New Member
Aug 9, 2007
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I currently have a 01 GT with minor bolt ons and a 100 shot.
Now does anyone know if going to a t56 will hurt my current 1/4 mile times?
also I'm running 3.90 gears with a Eaton 31 spline and tom's 31 spline axles (I blew up the rear end in Fontana early this month:shrug:)
I only ask cuz I'm sure the trans will go next and I know the t56 is stronger. Also I drive my stang everyday and wouldn't mind have 6th for freeway driving.
 
For the money spent and ur mods... dont' do it. It shouldn't hurt ur times although I imagine a t56 would be just a tad heavier than a t45/3650. I'd say if ur going to swap, buy a tko 600 with a 2.95 1st... u can still get a good over drive gear and keep ur mileage respectable.
 
I dont car for how my viper spec shifts. I could shift way faster with the five speed. But I dont beat on my car anymore so maybe I just havent learned to shift it yet. I was actually thinking of swaping to a tko-600 but it sounds like I should do some research about them first.
 
3.90 and a 6 speed...you'll prolly have to do some mad shifting. I saw a 95 Cobra with a 4.10 and a 6speed at the track and he said he was in 5th at the red line when he crossed the 1/4 mile mark. His 1st and 2nd gear were completely useless. I'd step down to a 3.55 or 3.73 gear with a 6speed.
 
Chances are, your 5 speed will feel faster, as the transmission gear ratios are a little different.

T 56 - 1st - 2.97 2nd - 2.07 3rd - 1.43 4th - 1.00 5th - .80 6th - .62
T 45 - 1st - 3.37 2nd - 1.99 3rd - 1.33 4th - 1.00 5th - .67

In my 98 Cobra, the 1st gear is harder as I have to give it some more revs to get it moving like it used to. If you're going to be dragging it a lot, you may get better times in your T 45. Where the T 56 really shines is in higher speed races (highway) where you're coming out of 4th. In the T 45 it'll fall flat on its face with a huge jump into its overdrive, where the T 56 will actually have a pretty usable 5th and start walking away with it. That really seems to piss off the Foxbody guys where they have an equal car, but lose because of the transmission running out of gear.

The T 56 also allows you to run some higher rear gears and not sacrifice as much street drivability, because you have those extra gears and a deeper overdrive. I'm not saying modular cobra/5 speed guys haven't ever run 3.73, 4.10, or 4.30 before, but they now don't have to cruise the highway at 3k rpm just to do the speed limit. Personally, I think the T 56 is a great transmission and wouldn't ever consider using anything else... unless they make a T 67 7 speed :)
 
3.90 and a 6 speed...you'll prolly have to do some mad shifting. I saw a 95 Cobra with a 4.10 and a 6speed at the track and he said he was in 5th at the red line when he crossed the 1/4 mile mark. His 1st and 2nd gear were completely useless. I'd step down to a 3.55 or 3.73 gear with a 6speed.

thats my setup. 3.90's and a 6 speed.

i'm crossing the traps in 4th at under 6000 rpm at 125 mph. no extra shifting required
 
i dont have a link but it is a direct swap. you need a new cross member and a 1" shorter driveshaft. the Viper T56 has the reverse sensor in the pass side, so you have to extend the wires about 6 inches.

we swapped a T56 in my buddies 5 speed car on the ground using hand tools in about 5 hours. if you have access to a lift it will be even faster. my swap took about 3.5 hours with a lift and air tools
 
D&D has everything you need in a kit. thats what me and my buddy are running.

i would recomend staying away from 6 speeds inc. they are cheaper but i waited 4 months for them to ship my buddies T56 that was PAID IN FULL. they kept giving excuses and finally i had to dispute the charge on my credit card. got the cash back, called D&D and had a new T56 delivered in 4 days!!!
 
Another way to skin the cat is to move your current transmission cross member back about an inch or so, and just get a custom or driveshaft specific to the swap. It's a nice transition, and bolts up rather nicely. D&D also does it rather nicely.
 
What bell housing do you use ? The 3650 doesn't seperate from its bell housing like a normal stick. The T56s do seperate and I'd provably get a viper spec one so the bell would need to be changed as well. At that point, I might as well go to a blow-proof bell housing/scattershield setup.

What scattershield works with these ?

As far as the mount is concerned, I would want to use a poly mount, I hate rubber trans mounts. Is there an aftermarket poly mount or will I be stuck using the stock rubber one for now until Energy or Prothane make one ?

Shortening the drive shaft is no big deal, I can also have a custom aluminum shaft made like I did for my 67. It wouldn't be TOO expensive to go that route.
 
DONT BUY A A SCATTERSHIELD. we got one for my buddies car and after buying it we found out the process for installing it was WAY more than we wanted to get into. you have to get offset dowel pins and line up the input shaft with a micrometer. we ended up selling it for a $100 loss and is was never even out of the box!!! the kits from D&D include a new bellhousing. the stock aluminum bellhousing will be fine.


what kind of power are you making?
 
Thanx for the advice on the scattershield.

The car is almost 100% stock. I did a cat back on it and will be replacing the factory H when I have time. I also put an MGW shifter in. I don't even have a drop in K&N. Any time I have to replace something or pull out a major component, I like to WAY over build what I put back in.

After my daily driver got smacked up by that dumb kid and I bought this Mach1, I decided to make my 67 the streetable race car and keep the Mach as a fun, mostly stock daily driver. A 6 speed would be GREAT for me considering how much highway driving I do.