After several people suggested the possibly that one or more components had an incorrect density or default value of 1. I assembled a simple lock washer (inch) into an empty assembly (metric), ran Mass Properties and compared the values (way off as I had said). I was about to cut and paste the results and send it out to show everyone what I was talking about and bingo (well I had a few other choice words here) there it was. Apparently someone changed our English start part unit setting to IPS ( Inch, Lbf, Sec ). The density units for the washer was Lbf Sec*2 / in / in*3. My values were off by a factor of 386 or the value of Gc = 386.4 Lbm In / Lbf S*2. Set the units back to Pro/E Default ( Inch, Lbm, Sec) and all is fine.
OK... long winded summary maybe but thanks guys for pointing me in the right direction.
Thanks again, DJ
"It took more than One Engineer to put One Man on the moon."