Thanks guys for the input. According to the ERA assembly manual & Web page, they lean towards the Toploader & Tremec transmissions.
Other transmissions will work, such as the Mustang T-5. However, evidently the Mustang T-5 has an integral shifter, so it does not exactly duplicate the original shifter position, and the shifter sits a few inches closer to the rear of the car.
The 289 cars have the short stubby shifter that sticks straight up, so I'll probably want to go with a gear box that has the shifter is the 'correct' location.
From what I have also read .. the TKO 500 has the 0.68 5th gear, while the TKO 600 comes with a 0.82 5th or a 0.64 5th gear.
If I do go for the 5 speed, probably want the 0.82 5th gear, hence the TKO 600.
Bottom line, I need to take advantage of the different calculators that are on line and do some more math.
- Tim