If you can grab you tie rods, wiggle them and have any slop when the tires are on the ground they need replaced. Your vibrations could also be a balance or alignment problem. I got my heavy duty clutch fan from Pep boys and I think it was made by Hayden. I put a 185 degree thermistat in it by Robert Shaw, it is the same as 302-351 windsors. A lot of companies make these just go to the parts store and check the manufatures charts, if they do not have any charts ask the parts guy for help. The 2 core radiator is made by Redy Rad or somthing like that. I got it from Autozone and I still have the box so I will get you more info on that in the day light.
I would go in steps. The temperatur sound right for stock.Is you temperatur high at stops in hot weather? First do The thermistat. Do you here you clutch fan lock up when its hot and you start from a dead stop? ( it should make a roaring sound) If not Thats a good sign it not working. The 2 core radiator adds about 1/3rd more coolant. after my mods I run at about the N or Normal on the high way in 115 degree heat and once my thermistat opens in town it never goes above the O ( at goes to the R then the thermistat opens and it drops) I have no need for watter wetter with this set up.

 

That's the way my heat gauge runs and everythings stock.

 

Well thats great . But you need to think about were people live and how they drive too. Yea its hot in Florida but not 115 hot and dry. Belive it or not but Humidity in the air is cooler than airid desert heat because humidity is water in the air and that is being pulled over your radiator, I do not have that. I also have steep mountains out here or steep large hills that tax the cooling system also. If I were to drive 10 miles on the interstate in 115 weather then drive stop in go through town for 8 miles all with the AC on my gauage would be 3/4 or over on the scale . If some one is towing with their van I deffinatly would want a 2 core radiator. My cousin has a 93 in Ohio and in the summer pulling a trialer in the hills of eastern Ohio his tep gage will go over 1/2. Now also if we really want to do it right we should replace the idiot gage with an elecrtic gage. I say electric because I do not think there is anywere to plum in the probe of a mechanical one and have an accurate reading. Now we would really know if our van is too hot or not. I do know the stock thermistat is 195 degee and I think that is too hot and prefer 185-180.

 

The 2 core radiator I bouhgt is a Ready-Rad model 112. I got it at AutoZone for $180 dollars. You will have to slightly modify your fan shroud to clear the AC compessor.