86-90 - I don't believe so. I do remember seeing a few Groove Phi Groove members in paraphernalia around campus. Never saw any Swing Phi Swing members.
I started A&T in '84. Finally graduated in '90. Pledged Pershing Rifles in 1986. There were G Phi G on the yard in '85. I believe there was an underground line. Somebody kept their stage plot (very choice real estate - flat concrete slab) right across from Williams Cafe, well kept and painted. At one point and time, the dean of students, after the Que line debacle, wanted to get their plot but was somehow sat down politely and it did not come up again. Finally, as I was the P/R Commander, we had a pledging / probate meeting with the dean as non-greek organizations. There was a member of G Phi G there. Never seen him before or since, but he was there.