These clips are installed in the square punched holes by inserting the short tab so it abuts the edge of the hole and push in the long tab in to the hole. While holding the clip in place with one hand, insert an awl or
similar tool to spread the long tab tight against its side of the hole.
To...
Actually, from a dead stop in drive, you can stand on it and it should drop (automatically-pun intended) into low gear. Then ease off the accelerator and it will probably bypass second gear and shift into high. Pretty cool ****** once you get all that monkey-motion linkage dialed in.
You might check to see if you have a phenolic spacer between your carb's base and the intake manifold. That will help insulate the carb from boil over/evaporation when you shut down.
Cruise-O was available from 58-62 for y-block cars. 61 and later featured a vacuum modulater. Other FE powered car green dot Cruise-O transmissions can be mated to a y-block if you have the correct converter, flexplate and bellhousing. 61 and 62 bell housings were aluminum and save about 50lbs.