Are you sure it's faulty dead centres Alan? You didn't get a good answer to your thread last month asking about your S7 turning tapers.
' Good afternoon folks, I have an issue on my S7 turning a taper. My lathe sits on a Myford cabinet. Using a test bar, a DTI and turning the "dumb Bell" I consistently get a taper ! it tends to be smaller at the headstock end. The taper however is variable. I have taken readings using different equipment.The saddle, crosslide and compound slide are smooth with no slack or looseness, As this issue is turning me to drink, I now hope some one can offer advice.'
Can you explain what the centre trouble is? Badly made Centres are a possibility, though two duds feels unlikely. There are a few tailstock issues causing similar symptoms. Always good to see a few photos.
Dave