I'm almost done with a 3.1 swap but it is time for the dreaded valve lash. I know the 2.8 and 3.1 have the same balancer but do they have the same timing marks. I can't see why a stroker motor would have a different timing mark. Does anybody know the rod to stroke ratio of a 3.1?

If you want to avoid a lot of grif later, assume nothing when it comes to those things. There are a few versions of dampers out there and they don't all agree whereas TDC and 10 degrees are concerned etc. Install whichever you brought and then set number one cylinder to TDC on the compression stroke and see if it matches the mark on the damper. If it didn't agree with the damperput a new mark there. Before you put that mark, remember you can be 180 degrees off and thus may have to turn the crank over to TDC again and don't turn the crank backwards ever to get back to TDC. If you want to pull the valve cover over #1 cylinder and watch the rockers, both valves will be closed as it comes up to TDC on the power stroke.