Re: 1973 65HP Johnson Steering question.
If you don't have a tilt tube built in its a 1972 65hp model and yes, there is a conversion kit. Its an aftermarket kit with a tube assembly that is bolted to the engine's upper mounting bolts. I have had one on my boat for three years and it works very well.
Although they are probably available from a variety of sources, I got mine from Donovan Marine, via my BRP/OMC dealer. Donovan is wholesale only, so you will have to go through a retailer.