Good source for new T5 transmission

Are you sure you want a T5 with that much motor? I think they are only rated for about 330 ft-lbs torque and you have more than that if you have 400 hp at the rear wheels. (HP=torque at ~5300 rpm.)

I found DD Performance http://www.ddperformance.com/
out of Michigan to have the best prices. You're borderline on how much that trans could take. You might want to look into a TKO instead. I believe your '68 has enough room in the trans tunnel for it.

Stangstore.com

is where I picked up my T5z for $1168.00 delivered to my front door.
Great people and great service.

I would strongly consider a high quality (not high "bling") shifter. I also found mine a little notchy at first on the 2-3 upshift. Take some time to break it in.
Also if you run drag slicks with a locker, or have real good traction, you may want to consider having it beefed up. There is a company out of Florida, I can't remember the name, that can build the T-5 to handle more than 600hp.

If you haven't all ready got your cross member, the one from Modern driveline is awesome! And I would highly recomend getting the longer speedo cable. I didn't and now I regret it, 'cause it's going to be bitch with the A/C installed. Eventually it's going to kink, just a matter of time.

Good luck, it's an easy and awesome swap.

Scott

T5z would be my vote for the street

It's only when you are pushing huge amounts of torque with a really hooked up rear and drag racing it's guts out, that you could possibly run into problems with a T5z.
This transmission is small enough that you don't have to worry about drive line angle issues. It comes stock with the Steel sleeved T.O. collar, the cup bearing, high nickel content gears and is such an easy swap.

I have yet to see anyone who has installed a TKO or other transmission end up with less than a 6* angle w/o modifying the tunnel. IMO that is too much angle. In the '66 (convertible) it is just a little over 3*. I did need to shim the differential 2.5* to get everything set perfectly. Picked up the shims at a local 4WD shop. Everyone kept saying "you don't need to". But for the extra 20 minutes work it's worth doing it right.

I would suggest a good shifter like the Pro comp. I added the Hurst arm on the stock shifter for my '66. Now that it's broken in, it has a good feel, but you still have to manually guide the 2-3 upshift. Some of the nicer aftermarket shifters spring load to third.

I'm really happy with it. When I finish with the rest of the car it will be behind a 400 lbs/ft torque + engine. I have no worries that it will do everything I need.

Good luck with what ever you decide. I think you will really enjoy the updated transmission. Really makes a big difference in drivability.

Scott