hey chaps its been a while but here goes .... all the above problems were caused by insufficient valve spring pressures !!!! ( valve float ) i got it to rev right throughto redline with an extra 0.60inch shim !! also i then found out my oil pressure was down so i have rebuilt the bottom end !! and guess what ! its still got a tap !! changed cylinder head today with standard item hoping it was just a worn head but that hasnt worked and it sounds like the tap is coming from inlet manifold, injectors or warm-up regulator but what could be causing this ??? i just want it ready for begining of summer so i can get to ford shows !!!!!!!!!