Hello, I hope the following assists.
The 75 PS and 90 PS cylinder heads are the same, the other higher power output cylinder heads differ. There is a head available at http://www.ebay.co.uk/itm/ford-transit-ldv-convoy-2-4-duratorq-cylinder-head-75-90-ps-01-05-/310799541480
with regard to the noise make sure it isn't the timing chain tensioner, as you are replacing the head I would recommend replacing the timing chain, guides and tensioner.
I hope this helps but let me know if I can assist further.