Done a fair bit over the last 4 days swapped out my old head for a fresh new ported head I've made myself, at first i had a nightmare getting the tolerances within spec , but magically the old head had the right size shims in to pass me through. Epic! Spec of the head is Toyota valve stem seals Toyota valve springs Polished combustion chambers Ported and polished exhaust runners Also took some material from round the valve walls in the chamber to help gases transition faster. One thing i noticed from the old worm our head that the cams were terribly worn , upto 1.14mm short lobes than the fresh one , most likely the reason I struggled to make power on the last mapping session. Then I managed to get the citoen/peugeot powersteering pump in and working , and works great , much better than having the no powersteering that felt notchy. It was abit of a faff getting it all in on my own, got there in the end thou.