Transmission suggestions...which one???

[bishop1911]

I am building a Shelby Clone and I am getting close to buying a tranny soon. I am putting back the 390 engine that the car originally had, but I am having it built from the ground up and it will be beefed up a bit. I have basically had myself set on putting in a toploader, but I am starting to rethink things. I spoke with the tech at Mustangs Unlimited and he suggested going with the Tremec 500 or 600. They can withstand 500 and 600 ft lbs of tourque. The question is would this be a better fit for me? I am not racing, all street and some spirited driving. I will be showing the car, so I may be taking it on the highway some and don't want the thing screaming. It does currently have 3.73 gears in the rear, which is what it had. The OD or 5th gear on the tremecs is .64 ratio, which I would think would be great for the highway. But my major concern is, will it last and hold up to the tourque and HP of the engine. I am not getting crazy, but the car will likely have about 400 HP and I am not sure what that translates into for tourque. Anyway, any suggestions and opinions would be great. Thanks.

http://www.mustangsunlimited.com/itemdy01.asp?T1=TR5008+01&Category=&catkey=emustang


Jon

 

[DukeGnarley]

I would think a TKO 600 would hold up fine, and would be better on the freeway.

 

[D.Hearne]

Better go with a Tremec 600 series. Stock 390's were rated to put out in the 425 ft/lb range. And you're right with 3.73's it will be reving it at highway speeds, but not too bad though. I've got 3.70's in my 68 Merc with 255/60/15's and a C-6, but it ain't too bad.

 

[Sicarius428]

Go with the TKO 600. The 500's gear ratio's would make your first gear useless and second gear too short with that much power. The TKO 600 is probably the best 5 speed for the price and will run circles around the toploader in shift quality and durability. The only other tranny to consider since you have a 390 and weight shouldn't be an consern is possibly a t56 for a .8 power gear and maintain the .62 overdrive and to be a tad different. Not sure how well it would fit though... TKO is a tad large compared to the common t5 swap. BTW a T5 would not hold up unless you get a gforce conversion.
Kevin