Correct shifter base model depends on OE configuration (per source vehicle). For TR6060 there are four versions - all are unique and not interchangeable without reconfiguring the trans. In all cases our bases convert to direct mount at location defined by OE configuration:
Viper & Falcon FG (Australian) configurations put shifter base on tailhousing
Challenger is remote OE but via a tail port that accepts direct mount base. Bolt pattern is unique to this model (different from Viper)
Most GM models + GT500 use a remote linkage entering through forward port on main case - which we convert to direct mount at this location
2009-2014 Cadillac CTS-V lacks any direct mount provision, must be reconfigured (swap tail or add forward receptacle)
Corvette - for swaps using complete C5+ Corvette chassis w/ rear-mounted transaxle
TR6060 did not exist before 2007; all prior to this were T56 which has a different shift rail architecture. If you have a T56, see the T56 swap base page.