Steve your gonna have a small problem. You need to check the 83 WP and make sure the fan connection orients the same as the 76 as far a location and distance. If your gonna use the oil cooler you cannot use the 76 pump. If you plan on not using it then you can just use the pump and thermostat off the 76. I'm pretty sure you can buy a 77 or later WP for a 55 that will have the oil cooler line. I know spending more money is a pain but you don't want to get that 83 WP you have right now near anything you just spent a chunk of money on. It's toast. The silicon was a temp fix due to the main seal being shot. Most likely this killed the bearings as they were sitting in radiator fluid.
I can help you source a new WP with a cooler if you want. I usually can find a good deal somewhere.
The 83 thermostat housing is looking a little rough. I have a feeling when you open it up you will see even worse. Looks like the PO of that 83 didn't know anything about radiator fluid. If it's not changed regularly it will start eating engine parts. It starts with aluminum first. If you want to you can bring it by to me one day and I'll but it in the bead blaster. It will give you a good idea of what you have and whether it's salvagable. Those 4 bolts holding it together will also be a pain to get out. Start soaking them now with PB blaster.
The 76 thermostat will work on the 83 as long as you don't plan on using the oil cooler.
Personally I'd see if the 83 thermostat housing is salvagable. If not I'd source a used one. Any thermostat housing off a 77 and above should work. Perferably from a 40 or 55. The 60 housing has a smaller radiator hose pipe which can be a pain when trying to use a stock 55 or 40 upper radiator hose. (ask me how I know (big gay leaks as I write this)). Those smog fittings on the side can be plugged. There is a thread in the 40 section on where to get the plugs on the cheap. If those smog fittings are in good shape I'd cap them and hit them with my bead blaster. They will come out looking new. People pay good money for those. I'd source a new pump from a 77-78 fj55 with oil cooler fitting. It will bolt right up to your 76 fan and put it in the right place. I'd still with the oil cooler routing. Even though it's a pain in the ass. There was a reason Toyota went to it on later 2F's. On the trail where your using high rpms and low speeds it could come in very handy.
I'd take everything you can to have it hot tanked. Everything! Ask the guys at 81 to do the tanking first and then go get them and start painting them. It will give you something to do until the motor is done. If your skeptable about getting the bolts back and knowing where they go I'd take pictures with them on a piece of paper with a ruler beside them and write on the piece of paper where they go. That way you can put them back in the ziplock bags that have the locations written on them.
The extra ports on the 83
I can help you source a new WP with a cooler if you want. I usually can find a good deal somewhere.
The 83 thermostat housing is looking a little rough. I have a feeling when you open it up you will see even worse. Looks like the PO of that 83 didn't know anything about radiator fluid. If it's not changed regularly it will start eating engine parts. It starts with aluminum first. If you want to you can bring it by to me one day and I'll but it in the bead blaster. It will give you a good idea of what you have and whether it's salvagable. Those 4 bolts holding it together will also be a pain to get out. Start soaking them now with PB blaster.
The 76 thermostat will work on the 83 as long as you don't plan on using the oil cooler.
Personally I'd see if the 83 thermostat housing is salvagable. If not I'd source a used one. Any thermostat housing off a 77 and above should work. Perferably from a 40 or 55. The 60 housing has a smaller radiator hose pipe which can be a pain when trying to use a stock 55 or 40 upper radiator hose. (ask me how I know (big gay leaks as I write this)). Those smog fittings on the side can be plugged. There is a thread in the 40 section on where to get the plugs on the cheap. If those smog fittings are in good shape I'd cap them and hit them with my bead blaster. They will come out looking new. People pay good money for those. I'd source a new pump from a 77-78 fj55 with oil cooler fitting. It will bolt right up to your 76 fan and put it in the right place. I'd still with the oil cooler routing. Even though it's a pain in the ass. There was a reason Toyota went to it on later 2F's. On the trail where your using high rpms and low speeds it could come in very handy.
I'd take everything you can to have it hot tanked. Everything! Ask the guys at 81 to do the tanking first and then go get them and start painting them. It will give you something to do until the motor is done. If your skeptable about getting the bolts back and knowing where they go I'd take pictures with them on a piece of paper with a ruler beside them and write on the piece of paper where they go. That way you can put them back in the ziplock bags that have the locations written on them.
The extra ports on the 83
even said she would buy it! I'm going to put a starter from my 76 in my spares kit for the trail unless that is a bad idea... I'm planning on bolting down a wooden box in the back of my Pig for trail spares: starter, birf, axles, diff, etc. 
. Head guy there said I would need new pistons, rings, lifters and cam...off to price that from the BG2F thread.
