i dont know enough about the series 2 heads to say what the benifits are.......... but if there cast iron - its not going to help with the compression situation. aluminum heads are going to be expensive.... very... compression is going to be hard to get..... just the nature of the beast!
I think you should really evaluate the situation... your shooting for NA power in a 3600lb car... this is one hell of a challange. Fuzzy has a real chance to do some damage, but he weighs the same as I .... 2300lbs makes a huge difference.
I just really think to do what your wanting, its going to take a Stage II in its circle track form. those made 450-500hp NA. save your pennys, 10-15 grand has you a built example.
All I know, is that my cousin Erik - built exactly like your wanting, huge ported heads- 10.5-1 compression, custom cam, edelbrock intake, 83 regal, Gneric built 200, posi rear, goodies and goodies........... and its a complete dog.... he has never hated a buick more since.
im just saying, before you drop alot of money on all these parts to really think about it... once the parts are bought your committed to the grind, and I dont want you to be as dissapointed as my cousin was... as he may never return to buick land.