there are dozens of formula which are more or less relatives of D-76 with a little bit more or less hydroquinone or metol or sodium sulfite. If you take less sodium sulfite you'll get a little bit more acuteness and a little bit coarser grain since the sulfite has dissolving properties for silver. But it acts also as a weak alkali (D-23 has only metol and sulfite), so maybe you'll have to adapt your times.