Hi Jason, the values you have are fairly common from what i have seen.  I did a
bit of work last year which needed that data too.
The website http://www.memscyclopedia.org/su8.html was pretty useful and it kind
of covers the point of do processing parameters matter also. It's also got loads
of other useful info on SU-8.
I haven't come across many papers which give a definite value but hope this
helps a bit.

Cheers, Dan.