ok, picked this up at a sale.....

[Tom Fleming]

Bought this at a sale, and recognize it (I think) as a valve tool of some sort. My first guess is that it is to measure seat depth or similar. The bushing is a 45 degree angle, and it measure vertical travel.

Sioux made it, but there are no part numbers anywhere.


 

[jackinok]

Ive never seen one quite like that exact one ,but back years ago we had a kit for grinding valve seats on flat head engines,it had a tool similar for measuring valve length ,since often you had to grind the length to set them. if i remember correctly ours didnt have a dial indicator,just the rod part,that you set and then measured the length of.
 

[JDseller]

It is used to measure the length needed on the non-adjustable valves in a flat head engine. I have one kind of like that. I also have the other piece that you drop the valve into and measure it. Buy setting one to the other you can get the clearance in one setting. I have not used them in over twenty years. I will have to look for them. I still have them as they where in a wooden box together with different angled seat/guides for the different engines.
 

[Earl-IL]

It is a special tool for adjusting stem clearance on a flat head Ford.Nice tool.
 

[T.R.K.]

The way I saw it used, the Old Timer who ran the shop used that gauge to set up his valve grinder so that he could grind the valve stem clearance in one operation.
He put the stem in the valve guide with the 45 degree bevel on the valve seat. then he adjusted it longer to the clearance he wanted and put it in the valve machine, it had a mating 45 degree vee for the 45 degree bevel, he just set it to the length he needed from the stone, swapped this tool for the valve and ground the stem to length.