If you wanted an LS1 to handle 600-700whp would you be ok with getting forged rods, and forged pistons that lower compression. Once you get compression down to 9:5:1 or so I should be able to run a procharger with quite a bit of boost right? I heard the crank is already pretty stout.

It seems like you can get forged rods and pistons, with rings made for No2, for under 1k.

Now can a procharger fit a RX7.. I dont know

 

Yeah it is more like 1200$. Sounds about right to me actually. Not sure if the procharger kit would fit an RX-7 though. Some people have turbo kits on them as well.
You might want to check on www.torquecentral.com there is a lot of people doing the FC and FD conversions on there that can answer all your questions fairly quickly.

 

yeah I have been spending some time over there as well, but all yesterday the site was running VERY slow and now its down.

The other big question. What do I use as a rear end if I have 600-700whp going back there?

The Turbo II rear end is more stout than the 10 bolt but not by much, still pretty impressive seeing how the car came with less than 200hp from the factory. Talk about over engineered.