Toploader torque capacity

[Dan859]

Hi Everyone,
I have a BP 482 stroker, 658HP, 636TQ.  I want to put a toploader 4 speed behind it, but I don't know how strong a transmission it is.  What's the approximate torque capacity of the small input and large input toploaders?  I plan on putting it in a 67-70 Mustang/Cougar, or a 66-69 Fairlane/Torino/Cyclone.  I like the idea of putting a Mustang II front end kit in the car, and I'd like to know what you guys think of the idea.  Is there a significant weight difference changing from the stock front suspension to that?
Thanks,
Dan 

[Joe-JDC]

Typically rated at ~450 lbft for small input shaft transmission.  The 390 was rated at 427 lbft from the factory, and that transmission was installed behind them.  Some sources claim 500, but I have not seen that printed from Ford.  Joe-JDC

[gdaddy01]

I like the mustang II front ends , give more room around the engine and more air flow . I like the looks of stock shock towers , but they do get in the way . not sure on the weight , 1964 falcon front end weight is 175 pounds , drum brakes , springs , steering linkage , etc. , plus the weight of the steering box , compared to rack and pinion . that was with bathroom scales so could be a little off .

[gdaddy01]

put it in the wrong place

[shady]

I  also always wondered if the big in out close ratio is stronger than the wide ratio? With less torq. multiplication of the first gear I would think the close is stronger, but I have no idea.

[cjshaker]

If you're going to be running it on the street, It'll handle quite a bit over a stock rating. It's when you start trying to launch them with good traction that will start busting things. On regular street tires, you'll be losing traction before you reach the limits of the big input. On a small input, you can start to twist the shaft after some abuse from a healthy big block. Not doing dumb things like side stepping the clutch or simply ramming it in gear will go a long way towards its longevity also.

I've had some problems with the small input, but I have yet to bust a big input on the street, but I'm about to find out if it can handle 490 ft.lbs. with slicks on a strip. Since I just rebuilt it last year and it has a new input and output shaft, I'm guessing I'll get away with it for a while, until the input snaps or the rear twists. If that doesn't happen, the helical cut gears will start causing problems with side loading.

[IDOIT4SPEED]

fun comes with a price

[Heo]

How does a T 10 and a small input compares to eachother?

[Joe-JDC]

Broken T-10s were the reason Ford went to the toploader transmission.  Most street driven cars will spin before they reach the limit of the transmission torque---for a while.  Might be time to consider a TKO.  Joe-JDC

[BH107]

For the second half of your question, I'm not a big fan of Mustang II. They generally have short control arms and even shorter shocks/coil overs that limit the travel. They are great for the streetrod guys because they are so easy to adapt to anything, but I would never personally use one. I've seen more and more guys going to a strut setup though, seems to be the hot ticket.

[Dan859]

Thanks everyone for their replies.  Given the torque that the engine develops, I think going to a TKO is likely the smart move.  I'm not sold on the idea of the Mustang II front end.  I do like the idea of opening up the engine compartment and getting the extra room.  On the other hand, I plan on driving the car on the street with maybe an occasional trip to the track.  I don't want to do something that won't work on the street, especially since I'll be in Upstate NY and the roads can be pretty bad.  Any further thoughts would be appreciated.  Thanks, Dan 

[machoneman]

On the bad roads, the OEM parts can take a real pounding if in good shape when you start out. The aftermarket Mustang II stuff, unlike the OEM Mustang II parts, aren't really up to taking a pounding over time in my book. I used to travel a lot on business as was always amazed how good the road were (and still are) in SoCal, FL, AZ and other generally southern states that don't suffer the freeze-melt-thaw repeat that tears up Illinois and NYS roads. JMO!

[garyv]

Dan I ran into the same quandry with deciding on a transmission to put behind my 511 Tunnel Port.
I built a BI/BO toploader for use but after the engine was dyno'd I realized that I was running the risk to tearing it
up and didn't want to take the risk.
My solution was to have a TKO 600 built that could handle the torque.
If you had a light car with street tires you would probably be ok with a BI/BO toploader but if you are running slicks and intend
to beat on it pretty hateful I think a TKO is the way to go unless you want to run a Jerico or a slush box.
A small in and out TL is not going to live long behind your engine.
Just my 2 cents 

[jayb]

I put an Art Morrison front clip in my 64 Galaxie, which is very similar to a Mustang II setup.  I love it, the car rides and steers so much better than stock with that setup.  The kit was also very complete and well engineered.  I would do that one again in a heartbeat.

I put a Fatman Fabrications front strut conversion into my Shelby clone.  That kit sucked badly, and I still have problems with it because it does not hold the steering rack securely, and the turning radius is awful.  It is relatively light, and leaves a lot of space for the engine if you cut back the shock towers, but it also required a whole bunch of extra work, chief among it a lengthening of the control arms, because the kit moves the wheel centers inboard by 2" on each side.  Naturally, they don't say anything about that in the kit literature.  Once it is aligned the car runs and drives fine with that setup, but I would never recommend it because of the poor quality of the kit.

[Katz427]

The toploader number was derived by pretty exhaustive testing and the Master Sargent has a good memory as 450 ft/lbs was the number tossed around back in the 60's. What one must realize is that was a number that still allowed an acceptable life cycle for the transmission. Slicks and  glued track surfaces put more stress in the equation as previously stated. If you have rebuilt with new gears the number would be higher as gear steels have improved quite a bit in the last 50 years. With modern gear steel 600 ft/lbs should be possible and have a decent life.