If you already have a 600 HP SBC then it kinda makes sence to do what you want to do but if you wanted to build a nice street car in its near stock configuration it would not cost as much as you think. I am working on a a 93 Lt1 6 speed project and when I am done I will have a 2002 SS clone with a low miles resealed Lt1 for less then $3000.

 

I have the engines built already, my street project 362 still needs a good set of aluminum heads before I can finish it, but my 377 is ready to drop in a vehicle. I plan to swap rear ends with a ford 9" for my drag car, hopefully the 4th gen, but as for my street car I have considered a 3rd gen only because the rear end is a tad bit stronger. I know that as long as you don't have slicks the 3rd gen would be alright, but I do intend to drag every car I build just to get some times in, so not sure which route I need to take