Torque Thresholds for the Ford Toploader 4-Speed

[Cal Metal]

For those experincing trouble with torque demands of other transmissions, here is a excerpt from a piece written in the early 60s that specifies the rigid requirements from Ford for the Toploader 4-speed. I will have Ron post the whole article later. Here is a quote which I thought you might find interesting:

"What does Ford demand of its transmission? All Ford transmissions must withstand 500 dragstrip starts as one part of their performance specifications. In a dragstrip start, a maximum torque of 1200 lbs. ft or three times the torque of the engine is developed".

[computerworks]

(...from Cal Metal)

This post contains two separate articles (3 pages each) pertaining to the development of the Ford Toploader 4-speed, plus a snippet of a rather dry SAE tech paper which discusses scheduling and management of the Toploader development.

The first article is an early press release, the second is an interesting discussion of the Toploader plant.

The articles...

[427 S/O]

I'm guessing this article refers to the big-in, big-out?

[Cal Metal]

I would assume that the requirements would be for both big in/out as well as small in/out as the Big shaft trannys were restricted to the 427/428/429 engines. The mainshaft diameters are the same for both transmission for the gearing and hubs mounts with the exception of a larger spline for the output in the "big out"(north of the rear bearing) and a larger spline on the input for the "big in"(north of the input bearing). The gearing on the mainshaft interchanges between both transmissions, contrary to popular belief.