I would like to interject this little tidbit into the conversation.
With all this talk of strong bottom ends, without correct modding and tuning to the head area, all that strength will be for no reason.
I would really do some research on what head work needs to get done in order to get the suck in and the bang out, as that is the most important part :P
As far as an N1 block goes... Waste of cash IMHO unless you want to build a straight drag car. No road race car needs the kinda horses that you would need an N1 block to attain