Hi
Not got a cat in hells chance that its not done any damage ???
Sorry to be the one to tell you that
cheapest thing to do is look for a second hand head or engine ??
If you start off putting valves in it it will cost an arm and a leg !!
Not that hard to find out of Xantia will not do off Bx or MI 16
A scrap car would be your best bet to get the engine out of might find one with suspentio probs on ebay going cheap
Its worth a look or in the loot WWW.LOOT.COM
God luck m8