There are many options available when it comes to these conversions and it can seem confusing at times. You can use a stock TKO and assemble your own conversion components or choose a pre-engineered package that will eliminate the guesswork and make for an easy transition to a smooth shifting 5 speed.
Stock: The Tremec TKO is a great choice right out of the box offering 2 shifter locations on the rear at no extra cost. The downside of this method is that it will not fit the factory offset shifter location on 64-67 models. If you're not using a console and converting from automatic, this may not be a concern to you. Flipping the shifter forward will position the shifter in the factory position for 68-72 models.
Modified: If you plan to use a 4 speed console or are converting a 4 speed car to 5 speed, this will be a much more attractive option. The transmission case is custom machined for these benefits.
More tunnel clearance is created. Cutting is still required on 64-67 models but there have been reports of no cutting on 68-72 models. Test fitting first is always recommended.
The lower extension housing mounting boss is machined away to eliminate crossmember interference.
Shifter pad is lowered .250" and a billet mechanism is installed for short shifts and proper offset for a perfect fit into the factory shifter location. Shifter detaches easily for installation and re-attaches without any re-sealing.
Positive spring biasing for enhanced shift performance.
Other hurdles exist such as your driveshaft and speedo cable. Choosing a kit will provide all of the necessary components and make your conversion headache free.
Info sheets are available to view here: https://www.facebook.com/media/set/?...1&l=5377eff2f5