Which 5-speed for a 306?

Forrest39

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I am looking at a Ford Racing 306 crate motor and am trying to decide what 5 speed transmission to put behind it. From what I gather, a T5 is good for 300 ft/lbs of torque and the z-spec might be good for 330. What have people been using? I am putting it in an Alpine V8 conversion and will be making my own tunnel so shifter placement isn’t super critical provided it isn’t ridiculous.
Thanks for any insight!
-Kevin
 

Jeff F

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I'll descent.

Having road raced and driven Fox Mustangs for longer than I'd like to admit, and gone through more transmissions than I can count (most of them built by Liberty in Michigan), I think a T5 is the better choice. While the TKOs are certainly stronger, they don't shift nearly as well as a T5 does, and are significantly bigger and heavier. In a street car, a well built 2.95 T5 will be fine behind a 306 unless you are really going to beat the crap out of it.

The best bet is to get a used box and have it rebuilt by someone like Liberty. You can retrofit a 2.95 into a 3.35 if needed, and you'll end up with all the upgrades like good synchros, shift forks, etc.
 

66TigerMK1A

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I'll descent.

Having road raced and driven Fox Mustangs for longer than I'd like to admit, and gone through more transmissions than I can count (most of them built by Liberty in Michigan), I think a T5 is the better choice. While the TKOs are certainly stronger, they don't shift nearly as well as a T5 does, and are significantly bigger and heavier. In a street car, a well built 2.95 T5 will be fine behind a 306 unless you are really going to beat the crap out of it.

The best bet is to get a used box and have it rebuilt by someone like Liberty. You can retrofit a 2.95 into a 3.35 if needed, and you'll end up with all the upgrades like good synchros, shift forks, etc.

+ 1 on that ! I've had one behind a 306 with around 400 hp for 6 years and lots of miles and still extremely happy with it :cool:


Jim
B382000446

Up until last year, the z-spec T5 was the best bargain out there! 330 ft./lb. is good for well over 400 hp , steel front retainer, 7 tooth drive gear and short throw shifter and it was $1295 brand new ! now they're $1695 :confused:
They also shift nicer than a TKO which requires different synchros etc. to be as nice as the T5 right out of the box.
 

Forrest39

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Thanks for the feedback. So the things I have to consider are:
1) For the price a TKO is near $700 more. Significant but if I blow up a T5, I'd be kicking myself. For the peace of mind should I just pay it up front?
2) The T5 Z-spec might be right at the limit for torque for the 306. But is it?
3) Weight and fittment. Is the difference in weight significant and will the larger size make my tunnel (which I have to make a new one anyway....) larger to the point where it conflicts with something else.
4) How bad is the shifting on the TKO? I plan on auto-crossing at some point - double edge sword here. a) I need it to shift well. b) If I miss a shift or drop the clutch a little hard on a T5-z because I'm being stupid will I blow it up?

There's no clear answer for me yet but I think I'm between the TKO-600 and T5Z.

Cheers, -Kevin
 

Moondoggie

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Thanks for the feedback. So the things I have to consider are:
1) For the price a TKO is near $700 more. Significant but if I blow up a T5, I'd be kicking myself. For the peace of mind should I just pay it up front?
2) The T5 Z-spec might be right at the limit for torque for the 306. But is it?
3) Weight and fittment. Is the difference in weight significant and will the larger size make my tunnel (which I have to make a new one anyway....) larger to the point where it conflicts with something else.
4) How bad is the shifting on the TKO? I plan on auto-crossing at some point - double edge sword here. a) I need it to shift well. b) If I miss a shift or drop the clutch a little hard on a T5-z because I'm being stupid will I blow it up?

There's no clear answer for me yet but I think I'm between the TKO-600 and T5Z.

Cheers, -Kevin


If you are going to autocross then you only need to shift from 1st to 2nd....
Like anything preparation is the name of the game setting up a TKO 500 or 600. Most driveline companies such as ( Modern Driveline ) modify the TKO's with modified shifting rails and carbon fiber lined blocking rings. The result is a
butter smooth 5 speed I have one in my Tiger. The old school rule " you get what you pay for " applies here when comparing the T5 to a TKO so if a little
is just good enough then twice as much is way better.

Moondoggie
 

Forrest39

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406
I think I'm going to look in this direction. Sounds like smart money. And perhaps a little room for expansion too!!!:D
Cheers, -Kevin




If you are going to autocross then you only need to shift from 1st to 2nd....
Like anything preparation is the name of the game setting up a TKO 500 or 600. Most driveline companies such as ( Modern Driveline ) modify the TKO's with modified shifting rails and carbon fiber lined blocking rings. The result is a
butter smooth 5 speed I have one in my Tiger. The old school rule " you get what you pay for " applies here when comparing the T5 to a TKO so if a little
is just good enough then twice as much is way better.

Moondoggie
 
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