To me this is very reminiscent of a DRATS record, "I'm Gonna Make It [[I Will Wait For You)". Both from 1967, these songs were departures from the HDH sound/formula that had worked so well for both groups:

LBLMHA was written by Richard Morris and Sylvia Moy.
IGMIIWWFYY was written by Debbie Dean and Dennis Lussier.

Did any of these four with one another, in any other combination?