There are several different combinations of TKOs available. First of all, there are two models, the TKO-500 and the TKO-600. The TKO-500 is a wide ratio transmission, which means it has a low first gear and there is a relatively wide ratio gap from gear to gear. The TKO-600 is a close-ratio transmission, which means it doesn’t have as low a first gear, but there is less ratio change from gear to gear. There is also an optional version of the TKO-600 with less overdrive than the first. The ratios are as follows, listed starting with the first gear and going up to the fifth:

TKO-500: 3.27: 1, 1.97: 1, 1.34: 1, 1.00: 1, 0.68: 1, 3.00: 1 in reverse

TKO-600: 2.87: 1, 1.89: 1, 1.28: 1, 1.00: 1, 0.64: ​​1, 2.56: 1 reverse (0.82: 1 fifth gear optional)

Although both versions are made of the same materials and have the same center distance between the axles, the TKO-500 is rated for 500 lb.-ft. continuous power output and the TKO-600 is rated for 600 lb.-ft. due to the higher (numerically lower) first gear ratio. Externally, they are identical and can only be distinguished from each other by the number on the identification tag. They weigh approximately 105 pounds. The box is 24.07 inches long overall and the crossbar mounting pad is located 15.8 inches to the rear from the front of the main box.

The TKO is available with a GM or Ford bolt pattern on the front of the box. All GM TKOs (500 and 600) use the GM corporate 26 spline x 1-1 / 8 “input shaft. Ford versions are slightly more complicated. The Ford TKO-500 can be purchased with:

1.) a 10 spline Ford long input shaft

2.) a hybrid long input shaft that takes the strongest GM pattern 26 spline clutch disc, but has the correct pilot diameter for a Ford pilot bearing

3.) an optional 10 spline short Ford input shaft (sold separately)

4.) an optional hybrid short input shaft that takes the strongest GM pattern 26 spline clutch disc, but has the correct pilot diameter for a Ford pilot bearing (sold separately)

Short input shafts are for older Ford engines that use a shallow bell (6.3 “- 6.5”). Long input shafts are for later model engines that use the deepest (6.9 “) bell.

The Ford TKO-600 is only available with a hybrid input shaft (long or short) that takes the strongest GM pattern 26 spline clutch disc, but has the correct pilot diameter for a Ford pilot bearing. Custom hoods are available to fit the Ford TKO to a Mopar small block or large block, along with custom Mopar pilot bearings to the diameter of the Ford pilot so the guys (and gals) at Mopar are not out of the fun.

All TKOs have a Ford 31 spline output shaft for added strength. Speaking of strength, both versions of the TKO are reported to be highly underrated in their torque capabilities. There are a lot of cars that drive hard, run TKO behind engines that put out significantly more power than transmissions are rated, and it’s rare for one to break down.

The TKO is a super strong overdrive transmission that can fit almost any muscle car or street rod, and can be mated to almost any popular domestic V8, V6 or I6 engine. For more information on Tremec TKO, take a look at my other articles in this series.