hi - i bought a new 200 block 5 years ago which had been machined for wire rings. it did about 150 trackday miles betwen gasket failures. always failing where the ends of the wire butted (it is worth reading the ggr web site discussion on this). i got pissed off with this gasket issue so stripped the engine. it took 30thou off the block face to get rid of the grooves and my head has been skimmed so many times it has lost about 1.3mm. to restore compression to 7 and a bit it needed very low comp cosworth pistons and a thick cometic gasket and the block has been long studded as well - fingers xxxsed but bin those wire rings!!