I take it you are measuring with the head removed. I'm not trying to get your back up but people do try that.
Do you have a mechanical advance rotor on your engine? You will know it because it has a lever and spring device on the inside of the rotor. You have to pre set that.

Sorry if this is a dumb question, but I'm installing new coil and points on my 1970 RT1 and this is the first time doing this. I don't have a buzz box, I do have a light, but not sure what to connect the light or buzz box to to make a connection to the points opening. Also, I thought I'd set the points and then there would be other screws to loose and move the backing plate (or ?) to set the timing. But it sounds like you just set the piston at 2.9 BTDC and set the points to open at that point. Does point gap not mater then? As long as they open at the right time? Also, my service manual is telling me that it's 3.4 BTDC. Thanks for the help, I just want to get this on the road!

250's are 3.2 & 360's are 2.9. In theory, having them crack free at 29 should give you a points gap in the 12 to 15 thou range using new points with unworn fiber heal. After some miles, [quite as few], the new heal will settle in so points will close down very slightly, so might need gaping them again, so check what gap they end up at fully open 'now' once set, & re-set to that. Think that's how it's done but not checked mine for a lifetime.
If yours has the advancer you'll need to hold that open as well. Some manuals cover both 250 & 360 & can be quite confusing at times.

Yes, set the timing by having points just open when piston is correct distance BTDC... with advance wedged open if yours has that feature. "Eyeballing" the points opening is not accurate enough... points will open several degrees before you can see them move. There are several methods or determining points opening if you search forum. If you decide to try to eyeball it, then try to set timing retarded... say at 2.0mm BTDC and you might be close. You do not want a 360 to be advanced even a little more than the 2.9 spec or you might injure your leg or break parts when it kicks back.

Thanks for the info, but I don't have a buzz box and when I've gone to several auto parts stores, none of them knew what I was talking about. Where can I get one? Also, what do I connect it too? One is to ground, but where do I connect the other lead to get the points opening? Thanks