This page for the '79-'83 250 power steering pump and brackets
] seems to show there is at least one mount on the integral head intake that is used to secure the current pump bracket in place at the back left upper corner of the bracket.
In the Parts Book (Jan '84) listing, it says GM# 473385 is the pump bracket for the '79-'83 250 application.
A check of an early parts book (Feb '83) for the non-integral head power steering pump mounting bracket
] shows a very different looking bracket.
The GM# 355788 (for '73-'74 250's) or an even earlier style bracket set up will be needed to reinstall your power steering pump if you change to a non-integral 250 head from what I can tell. Unknown if this may also involve a change of the pump or other related items to get everything lined up and functioning properly.
Hope this may have been somewhat helpful.