My car has been on blocks for 5 years. Last time the motor was in it steady blue smoke came out the tailpipes. Engine was rebuilt has only10k miles on it. Was told could be bad or cracked valve seals, rings, bronze valve guides worn out. Motor is out of the car. What is the best way to tell what needs to be replaced? Iron Heads have machined teflon seals. block was bored .030 with forged pistons.