Don't fret about working on the floor or short side radius - the short side of the head and the intake and lower intake runner roof where it turns into the lower are actually where you'll find some more flow. Just don't get carried away.
I have a bunch of ported intakes out there - stock lower and Cobra style lowers - on Stangnet,Corral,50Tech and maybe one or two from this site. Rather than buy all those rolls, I'd suggest buying a couple of "double cut" carbide burs for both the heads and intake. If you don't use much pressure on the bits the bite soft and don't take a bunch of metal out. Just take your time - you got plenty of that - go to:
www.carbidebur.com
get one "Flame (SH)" and one "Taper (SL)" bit in a 3/8" diameter.
go to
www.veryuseful.com/mustang/tech/engine
and download my basic instructions on porting an intake. Taking measurements with the tools I recommend will keep you from breaking through of the runners.
__________________
Tom (Torque) Moss
88Gt 5spd Vert, FLowmaster Catbacks, stock cam advanced 4° @ 108.5° ICL, NMRA prepped GT40P heads 1.85/1.55 valves and 1.7 rockers, MAC P headers Jet-Hot coated, 97 Exlporer intake (ported lower), TB and injectors. 277RWHP/330RWTQ (SAE).
http://www.fastlanecars.com/