Im doing a 73 5hp briggs engine for the build off an.im.stuck the bolts on my carb an tank wont budge they are stuck on an the screw driver is stripping the head I dont know how to remove these do I.use pb blaster on.it can I.use a little heat on them or a screw extractor tool to.remove I.need to.get thede out so I can.move on.thanks ...