a small block should be at about 8 degrees advanced at idle. although i've seen a few run at 27 degrees advanced though and it ran. when it was running how did the truck run? did it run really good or did it have a hard time keeping an idle? how did you check the ignition module? it can look good but still not work.
underneath the dash i think it's either a 15 amp or a 20amp fuse for your ignition coil