Edelbrock RPM intake upgrade to RPM II intake?
Yes, possible 10-20 HP over the standard Edelbrock and you may be able to replace just the upper. Not 100% sure, you'll have to check.
1.6 rocker arms to 1.7 rocker arms.
No, I don't believe the gains are worth the additional stress on the valvetrain.
24lb injectors to 39lb injectors w/MAF
(P.S. Corrected that for you.)
24 to 30's, Yes, According to This Page
you are close the the limit at 80% duty cycle.
More information Here
BBK shorties to long-tube headers.
Yes, There is an additional 10-20 HP to be gained with the swap.