Well, NA, you can spin that **** to the high 7s but you wont build power doing that. The heads and cams, like duffy said cant supply the A/F to do so. Mark VIII engine. Treat it like a GT engine with say, 500 more RPM. Don't expect to spin it to 7K and build power. Cobra intake and what not, spin her to mid 6k 1-2 and low 6K 2-3 and you will do okay.
Forged or cast crank, don't worry about the RPM under 8K less you build some crazy HP.
A cast crank, rod and h.p. piston assembly will make more HP, than a forged crank, rod, piston, assy. will any day of the week NA all other specs the same.
As for info you are looking for. We don't have enough info. We need to know how far you are looking to go. I will assume you are looking to maybe work your heads over, keep your cams and throw them on a mark viii SB. You won't gain RPM at all really. It will be much like your stock engine, minus some overall weight in the car.
Mark viii engine?
Sucky torque curve, with useful RPM in the low-mid 6K range with a cobra intake. 93-98 mark VIII engine basically= to 99-04 PI 2V engine with more RPM extension.
De-stroker kit? Time to do some research dood. You list NONE of your goals, or what you would like to achieve. Where Did you come from?