is this guy blowing smoke up my you-know what?

[EEYORE5182@aol.com]

ok, i finally got my welded tranny installed.  i went back to get the old
tranny and the car, and the mechanic who put it in said he filled my manual
tranny with ATF!  he said somthing like "dont worry, its fine.  dont let
anyone tell you different.  gear oil will make the shifting harder in the
cold.  it will be ok.  i have done this for a while".  so, is he right or
should i dump the fluid and go get some syncro shift or motul or something?
that is what i was planning on anyway, but the tranny went in without much
planing (longer story) and i didnt have any oil for it.  i just figured they
would put some manual fluid in it and it would last me.