It is very easy to get caught up with big dyno figures (or low for that matter) but the relality is this-
Dyno's, particullaly chassis dyno's can vary greatly from one dyno to another.
I have seen variations with the same car of up to 30kw.
Same day, same car, same fuel batch - 3 different dyno's (long story)
What you should be more interested in is the percentage increase (or decreases) of the before and after modifications dyno run/tune.