I just swapped a super turbine 300 for a TH350 and everything went according to plan, except I can not fine any help on the shiftier! I have the original Chrome T handle with a black top for the 2 speed I see there are kits available to convert it to a 3 speed but can't get the answers I want before I buy it. Meaning, Do they bolt to the side of the shiftier for the handle to catch like a de dent? see picture. I hate to spend money on something that wont work! Help would be appreciated

Ames performance engineering has exactly what you need and yes it is a detent/slotted piece that bolts up. Their kit comes with everything you need including the lever bushing hardware and a new shifter lens with PRND21 on it. I have never used it but a friend has it in his car and it works good and was fairly inexpensive.

Thank You

X2. I used Shifterworks kit when swapping in an overdrive transmission. Works good. Some work to install the detent plate.