Quality is going to suffer greatly, even with a two stop push. When I first started processing B&W around 1974, I used to push Tri-X to 1600 all the time (What did I know?) Looking back at those pictures that survive, it was a big mistake.(posted 8185 days ago)Your best bet may be to push two stop and accept the lack of shadow detail that you are going to have anyway. You don't say what the subject was, but you might be able to turn these shadows into a feature.