I have a 1986, 175 Hp Johnson. About 5 of the bolts of the water jacket are rusted. I would like to replace these. Will I warp anything if I replace them one at a time torquing each new one before removing the next one. The other approach would be to remove all the bolts and tighten them in sequence. I have a Clymers manual but don't see the procedure for this in their instructions. Help is appreciated.<br />SilverBob