Calculate data on 2 different worksheets

[jc]

I have a very large workbook and for efficiency reasons I
have calculation set to manual. I need to calculate 2
different worksheets, but because they refer to each
other, I have to calculate them a couple of times to make
all of the formulas update correctly. I've tried naming a
single range:

Range3 = range1,range2

then I use Range("Range3").calculate

but the result if only one iteration thru the formulas and
the final result still needs one more calculation.

Short of putting all the data on one sheet, is there
anyway I can insure 2 separate worksheets are completely
calculated?

F9 is not an option, the workbook is very large

thanks, jc