You‘re going to need more than a spare drive shaft..you will need the whole jet pump unit. The drive shaft presses into the bearings that are pressed into the jet pump casting.
Glen at Impros will take good care of you, he did the work on my impellers.
I can swap out two impellers in about 40-45 mins start to finish on both pumps if I do not have the Loctite sealant on the bolts, it takes me about 90 mins to do the same job if I had put the Loctite sealant on the threads of the bolts as I clean it all off with a tap and die before re assembly. I am meticulous when it comes to re assembly so that everything goes together smoothly and all threads are protected by using the sealant if I’m going to leave the bolts in long term.
You should be able to do a single in 30 mins or less, after the first time, the first time may take you a bit to clean all of the factory sealant off of the threads and it would be the first time so there is a bit of discovery going on. If you are going to be swapping the impellers out on a regular basis you can get away with not putting the Loctite thread sealant on the bolts that hold the jet pump assembly in, and just put a little dab on the impeller threads itself as long as you are in fresh water. If it is salt water I’d put the sealant on the threads every time.
Use the loctite products listed in the shop manual, as well as the molybendumdisulphide grease on the shaft splines. It also goes pretty quickly if you have a way to drive the taps with a drill at a very slow speed to clean out the larger bolt holes. Use the thread sealant sparingly, just be sure the threads that will interface with the housing have some sealant on them, but down in the grooves not laying on top. I put the sealant on the threads and smoosh it down into the threads and then use a paper towel to wipe off the excess, too much and it will make a mess that you will have to clean up the next time. The gasket eliminator just needs to be a thin skin on the mating surfaces on the transom plate and then bolt the pump assembly on, this stuff is really nice as it doesn’t really go off to a hard finish, it stays relatively tacky.
There are lot of pump removal and install posts on here so you should be able to get a very good idea what is going to be involved. Be sure and have a shop manual and study it before hand I think you will find it is pretty easy job.
