I hate to be the bearer of bad news but, a crack in a windshield will never get better only worse. As the temperatures outside of the truck goes from warm to cold this action will cause it crack more. Some states will reject vehicle if crack is in drivers field of vision as well. Best bet, suck it up and have a new one put in, Most insurance companies cover this if a rock hit it etc, so check save yourself some cash and while it is out have a new gasket installed as well. I have already had to do same with my '83 longbed. Good luck!