Hi Guys....I have an old pair of 074 winters aluminum heads...my question is I,m looking to drill and tap the rocker stud holes and install my own type of heli coil-time sert...only I can't find any info on the angles of the holes....basicly the head dimensioning machining drawings...local speed shops not much help at this point...just wondering if theirs a book or drawings on the net somewhere.....thanks in advance