I don't use a gage on my 1976 Bristol 24 rig. I get the stick standing straight up, side to side. I allow about 1 degree forward lean on the mast, to lessen weather helm. With a new main, I set up with no lean.
The uppers should be hand tight, then a little more with a wrench. I leave the lowers hand tight. If the lee shrouds are too loose when sailing in heavier wind; I give each turnbuckle an extra turn, until there is just a slight slack when beating unto a stiff wind. All this assumes your mast step and support are good.
Properly set up, you should be able to beat upwind with a 150 genoa, and have almost no helm pressure, even with the rail down.