Tranny 4-speed or 5-speed Hmmmmm!

[Sizzler]

This has been posted about before; I found it interesting.
You can have your cake and eat it too by installing a toploader initially, getting everything dialed in, then as funds allow, and if you STILL want the overdrive, you can just bolt on this unit to the end of the toploader. Most people think of add-on overdrives as being for automatics only, not so apparently:

http://www.gearvendors.com/racing.html>

GEAR VENDORS makes a kit to fit the Ford Top Loader and Jerico transmissions. The .78 to 1 ratio gives 28% more top end to the vehicle numerically and can be used in a variety of ways for the racer. Since the GEAR VENDORS can be shifted without clutching, it is decidedly faster when compared to a conventional shift. Imagine coming out of a corner or racing down a dragstrip where a foot or two could be very valuable and you have the option to hit a .78 multiplier under full throttle.

Some drag racers have found that using the overdrive version (popular in road racing) of the Top Loader with the ability to clutchless gearsplit the wide ratios makes for a great 5 or 6-speed.