Thats the same problem I ran into, no the intake will not fit on earlier style heads. What I did was to use my stock heads from my 88 chevy, I ported them out, rebuilt them, etc, and put them on my new 355.
What you could do if you wanna, it would be a long shot but you could get a nice set of vortecs, and a vortec TBI intake, since they have a different bolt pattern. You'd get a lot more power out of your 355 since the heads currently on your 1990 are pretty restrictive.

-cory