87 3.0 L TD block , has it sleeved, installed stock pistons, replaced rings, chains, all bearings, guide rails, head was rebuilt, new tappets. Put it together, started right up after bleeding the lines. I noticed a ticking (tapping) coming from the head. I took the pre chambers out, inspected them, a few had silver residue full of carbon. I re installed with shims started it up, the noise still there. I checked the timing TDC with the cam it seems to be right on. I'm checking it with a dial indicator tomorrow .. I used a head from a 3.5 L 91 350SD are they compatible ? I used parts from, both 3.5 3.0 L in the build. Any Ideas ? all help welcomed ?