My 544 had the transmission rebuilt back about 10 years ago. They gave it back to me empty of antifreeze and with the temp gauge capillary broken. Obviously it overheated. The head gasket went within weeks, and a 3rd party was involved to check the head for cracks and to rebuild it. This 2nd shop couldn't find correct b18 (.341") valve seals, so they put on b16 ones, which split. /car poured blue smoke.
Second secenario (5yrs ago) b20E head: sealant used by me to seal headstuds got into the oil passage to the rocker shaft, resulting in no oil to the top of the engine, and a squeaky sound that replacing the water pump and alternator did not fix (ie. it was the rocker shaft w/o lubrication!!). The seals wore away because they were sliding on the chromed stems./car poured blue smoke.



Why these sad stories are relavent:
Whether the valve guides were incorrectly fitted as to clearance, or not, (they may well have been in the first case, they definitely were not in the second) both engines began *pouring* blue smoke on start up and a fair bit on deceleration. The second also required the valve seats to be redone because there was so much carbon build up on the valves and the valve seat area, that the valves were not entirely closing and had begun to burn.