Hello again. I have 97 454 XLI's, and am about to replace the OSCO 9015's today with the OEM Crusader Barr Lower profile risers. 1st) I have been spraying the nuts for the last week hopefully they will remove easily. If the risers are hard to remove is it right that I read I should use a 30lb BFH? Would that crack the manifolds? 2nd) What type of gasket sealant does anyone recommend and finally 3rd) I have a rear mounted HEX the only thermostat is in the house leading into the HEX. How do I purge "Burp" the system so there are no air pockets in the coolant system? Thanks Again for all your help.