ok, here is the finality of this thread. first off, SRK and 1990LS400 you were right about the setting me up, lube etc. The second mechanic replaced the valve cover gaskets, spark tube seals and vent seals. he showed them to me and in his expert opinion they are all the originals from the factory. that was the whole problem, they just needed replacing. (although, that is the 4th time I have paid someone to do it.) so no new engine needed. you guys were right on. Thank you for all the help.