good penetrating oil?

Working on trying to get the alternator of my son's '94 Ranger pick-up. Have 2 of 3 bolts off. This third bolt is in a pain-in-the-butt location. Cannot get a regular socket on it because of minimal clearance (frame in the way). Can get a 1/2 open ended wrench on it but the bolt is so locked into place that the wrench is starting to strip. Have been using WD-40 on the bolt to try and loosen things up. Is there a better brand of penetrating oil/fluid I could use?

Would like to get the alternator off myself but will take to my local mechanic if I can't get this last bolt off. Any ideas?



Glenn