will cosworth head fit my w124? help!!

first of all let me expian the engine in my 1987 w124 200. i have just bored it out to 2.3 litres and replaced all the gaskets etc etc. but i have a friend who owns a 190 e 2.3 16v cosworth. his car is ridiculusly fast and burns tires like they were bread.

i am am lusting for that sheer power and acceleration that only it offers. what i am asking is, will my now 2.3 litre block be compatible with a cosworth 16v cylinder head? it has according to the haynes manual i got the same bore and stroke as my machined engine now has. i need to know if the compression would be diffrenet and perhaps more importantly if the pistons in a 16v engine have got valve clearance slots grinded into them. my car has a manual 5 speed gearbox. will fuel econemy be much worse than it already is?

if anyone out there has a cosworh head please reply and i will glady pay up to £400 cash for it. (if it will fit)