When u go to remove the exhaust head studs (if u need to) run that motor till the top end is hot, grab a $3 dollar can of that spray keyboard dust off stuff, hold the can "upside down" (gets freezing cold) liberally spray the bolts one at a time then try to remove- damn thats a long sentence......
coarse as u know they may break any way but.. well thats my 2-cents worth of info
good luck
shep
looking good by the way.