I have the t56 in my superformance and love it when cruising. If you want to make noise stay in fourth, if you want to cruise quietly (???) and economically (???) then keep doing some more research. I went with the viper t56 for the added strength FWIW... good luck..

Have the best of both worlds, put in a 5 speed and "graft" a four speed shifter to it to look like a four speed........That's what I did in my 65 Fastback....and love it....how many people are gonna crawl under your car to see what trans you have in it????????

At car shows or cruise nite, they ask if I have a four speed in the car, I tell them YES, and I do, the trans has four speeds, it also has five speeds, but they didn't ask that........:):););):LOL::LOL:

David

That's like the answer to the question "How many months of the year have 28 days? ALL of them!"

Huh? What do you have under the hood, a pair of hamsters? My 527 puts out enough noise to match a gang of Harleys.. I'm getting old enough that I care more for my hearing that cool...

BTW, I have a TKO600

With that much engine you could run 4 or 5 speed.My car started out with a 460 ci,TopLoader 4 speed, and a 3:54 rear.Except for highway driving it worked quite well.Now have a little more hp, Tremec TKO 5 speed,and 3:73 rear.Amazing difference,out of the hole and much faster highway cruising.

Oh well...cruises down the road at 2100 RPM and it sounds pretty good now. If I want noise, I just crank up the bike.

4 speed,5 speed, 6speed, 7,8 whatever
 

Al G Al What you need to do is look at what camshaft is going in the motor, how big the motor is going to be, what you are going to do with the car. Cruise, Show and Shine, Autocross, 1/4 mile abuse, Roadrace and at what track. You said you are looking for about 500+HP. THis is nice for the top of the rpm range but looking for a torque number in the 2,000- 2,300 rpm. This is the range where the motor will spend most it's time when driving. This is with an overdrive trans. Is this 427 going to be stroked? Changing the crank shaft and going to BBC rods is a good idea, You can run lower compression and not have to use and carry octane booster with you.
The important question we have to ask is have you owned a car of this power before? There are not many cars or bikes with the HP to weight ratio of a cobra. There are no ABS brakes unless you find a company that can install a setup, no traction control, your right foot only!, P/S is only in some cars. This car is great, cool, fun to drive, and also has killed some CC memebers. Driving school should also be looked into before going on the street. I just want you to know the facts about this car and the respect it needs and gets. Can you fill in some of the spec of the car a little better, please. We can then give you an ideal solution for your questions.
From what you have here, a stroked 427 block in the 470-490 range. 10.0 compression so you can use hi test with boosters. cam shaft of hydro roller in the 580-620" total lift. A 3.07 rearend ratio. A 5 speed richmond super street trans than will take the abuse and bolts right up to the bell housing without any spacers or changing input shafts. Stock handle will bolt up to it and look OEM. .86 overdrive trans with a 2.70-2.80 first gear. This is a good starting point. Rick L.