Big update, not done one for a while!
I got bored waiting for the head so the block has been painted including the gearbox, the starter motor, alternator and distributor have been overhauled and painted, radiator cowl painted all rubber fuel hoses replaced and all the engine steady bushes.
Next up I bought a modified plenum chamber, blanked off the overboost valve and fitted a Bailey dump valve.
Managed to finally get a decent stage 4 head with only 2000 miles since being built. I drove all the way to Telford and back one evening to get the head as I didn't want to risk getting another cracked head to add to my growing collection of scrap cast iron!
30mm Nitrided stainless steel race exhaust valves
36mm Nitrided stainess steel race inlet vlaves with waisted stems
28cc Chambers, Silicon bronze bullet nosed guides with boss restrictions removed, 3 angle valve seats, 185lb double springs and polished / ported
The only problem with the head is that it was missing a hole for a water temperature sensor being a metro turbo head so Dickie from West Sussex Mini Club kindly drilled and tapped the hole for me.
I stripped the head bare which is very hard work getting that enamel engine paint all off. I used a screwdriver as a scraper, wire brush and paint stripper and a lot of elbow grease.
The instructions on the paint can stated warm up engine before applying paint and as the head was not in the car the wife's oven done the trick
I applied 2 coats of acid etch primer, 1 coat of red oxide and 3 coats of engine enamel
I striped and rebuilt the head fitting new valve guide seals just to be sure, cleaned up all the threads and swapped over all the studs.
A few hours after having all the right bits and it's back together. New oil, filter, antifreeze, plugs and fuel filter to finish the job.
Video here >>>[video]
http://www.facebook.com/v/10150162787044447[/video]
The crack extends right through both inlet and exhaust valves and a good 1cm deep into the valve chamber rendering the cylinder head pretty much scrap 
