Positive Stop Tool: By John Cailey

When degreeing in a cam, the most accurate way to find true TDC (top dead center) is with a positive stop tool.  You can buy one for around $30, or as I did, you can make one for almost no money.  The one in the picture is for a small block Mopar and the dimensions are as follows: 

I started with a scrap piece of flat stock 1 1/5" wide, 7" long, and 1/4" thick.  I drilled two 1/2" holes on ether end 5 3/4" on center.  Centered between these two holes I drilled a 29/64" hole which I tapped with a 1/2" -20 tap (sae fine thread).  That's all there is to it.  I use a 1/2 fine thread bolt and nut in the center hole to set my stop distance.    If you want to get fancy you can slot one of the end holes and give your tool multiple engine capabilities.