They are actually the same as carburetor studs, coarse thread into the water pump, fine thread for the nut.
Ya, so far no luck on getting them out, guess I'll have to get them from the part store. Also, like I mentioned before, some bolts were not there before I started. How many bolts are suppose to be in the installment???
The studs will come out with effort. Sometimes people put Loctite on them. Like ap1672 said, 2 nuts lock them up against each other tight and wrench on the one closest to the pump body. Wedge a big screwdriver or pry bar on 2 of the others to stop the pump from turning. Not sure how many bolts on a 350. But...like 4 longer larger ones, and many smaller ones that are all the same size 9-11 of them? A few holes on the pump are for alignment pins that SHOULD be on the timing cover. Those are press fit, the holes on the timing cover should not be threaded where they go. They are sometimes missing. There are holes on the pump that LOOK like bolt holes that are for those pins.
.............and get the studs all loose before removing any of them so you can use the screwdriver, as leverage, on them all.
I am considering using studs n nuts instead of the small bolts next time around . anyone tried that ? seems to make sense .
Thought you were working in a garage, not a closet. Glad it was the studs that came out. Run a thread chaser in all the bolt holes on the engine before installing the new pump. It'll make it much easier.
I convert every water pump I change over to studs. Makes it much easier to install the fan. I use small flat washers and nyloc nuts.
I removed one of my intake manifold plugs on each of my Buicks, and installed a modified sacrificial zinc, just like on a marine engine. Older Buick engines are like a giant battery. Iron, copper, brass, lead, steel, solder, etc, all tied together with water, and when the water has any dissolved elements in it, you just created a battery. I also replaced the wet water pump bolts with stainless ones, with sealant on them. Not concours, but now trouble free. One engine, in my '69 GS350, was built by me about 26 years ago. Water pump bolts are fine. I usually just put in threaded inserts before I install a front timing cover. Much easier when it is on the bench. I managed an auto parts store for 4 years, and I could always tell how often a buick engine's owner changed their coolant, by how rotten their water pump's core looked.
I had this thought when I replaced my water pump a couple months ago, but didn't change over to studs, got impatient. Yup one is torqued to a low value. But it isn't leaking, so I'm going to wait until I have to replace the water pump. Which is going to be a long time from now (unless it starts to leak), because I take care of my coolant. I can't control the previous owner's lack of care, though.
there are 4 long bolts that goes thru the timing cover,three are the same length the other is a little longer. it maybe they switched the bolts around that is why the washers.check the length of them cause one might be grabbing just a few threads if it is the wrong hole. the long bolt is in the hole under where the hose connects.