Today i have changed all the core plugs,10.70 for the full set inc p&p from graham walker.The ones that came out were in poor condition, they looked ok from the outside but were very rusty on the inside and were nearly holed.I also blasted out the crap from inside the block while the core plugs were out, with my airline off the compressor,you should have seen what came out. i bet the engine is lighter now !!!